CWE-1050
AllowedExcessive Platform Resource Consumption within a Loop
Abstraction: Base · Status: Incomplete
The product has a loop body or loop condition that contains a control element that directly or indirectly consumes platform resources, e.g. messaging, sessions, locks, or file descriptors.
31 vulnerabilities reference this CWE, most recent first.
GHSA-8RR7-CVQ3-GMFH
Vulnerability from github – Published: 2026-09-01 20:28 – Updated: 2026-09-01 20:28Impact
AttributesExtension ships with the library but must be explicitly registered on the Environment; it is not included in CommonMarkConverter, GithubFlavoredMarkdownConverter, or GithubFlavoredMarkdownExtension. Applications that do not register AttributesExtension are not affected by this advisory.
Two paths in the extension re-process every attribute a node has already collected each time another attribute is applied to it. When the attributes carry distinct names, the collected set grows by one on every step and is walked again in full, so a run of n attributes costs O(n²).
1. Attribute nodes resolving to a common target (affected from 1.5.0).
AttributesListener::processDocument() merges each attribute node into the set accumulated for its target, then filters the result. Both operations traverse that entire set: AttributesHelper::mergeAttributes() rebuilds it with array_merge(), and AttributesHelper::filterAttributes() matches a regular expression against every name in it. A run of attribute nodes sharing one target therefore re-walks a set that grows by a key per node.
Two input shapes reach this path: adjacent inline attributes at the start of a block ({a0="v"}{a1="v"}…, where quoting the values is what keeps them separate — an unquoted value swallows the }{ that follows it), and a chain of attribute blocks held at their default target by reference definitions ({a0=v} / [a]: u / {a1=v} / [a]: u / …).
256 KB of adjacent inline attributes takes 20.0 seconds to convert, against 0.09 seconds once patched.
2. Consecutive attribute-block lines (affected from 2.0.0).
AttributesBlockContinueParser::tryContinue() merges each continuation line into the block's accumulated attributes, again rebuilding the whole set on every line. One distinct attribute per line ({a0=v} / {a1=v} / …) grows it by a key each time.
256 KB of such lines takes 1.9 seconds to convert while producing zero bytes of output, against 0.08 seconds once patched.
Relationship to GHSA-jjv6-8j6v-6j52. The fix released in 2.9.1 for that advisory made the class attribute cheap to accumulate, but left every other attribute name on the original path. Applications that upgraded to 2.9.1 or 2.9.2 remain exposed to this variant.
Overall impact. An unauthenticated attacker who can submit Markdown to an affected application can consume disproportionate CPU time with a comparatively small request, occupying PHP workers and preventing legitimate requests from completing. The impact is limited to availability: no data is disclosed, rendered output is unchanged, and no rendering restriction is bypassed.
Patches
The issue is patched in 2.10.0. Both paths now fold each node — or each line — into the accumulated attributes at a cost proportional to that node or line alone, rather than re-merging and re-filtering everything gathered so far. Rendered output is unchanged, down to the order in which attributes appear.
The listener path affects 1.5.0 through 2.9.2. The continuation-line path affects 2.0.0 through 2.9.2. The 1.x release line is no longer supported, so its users must upgrade to 2.10.0 or later.
Workarounds
If you cannot upgrade immediately:
- Do not register
AttributesExtensionwhen converting untrusted Markdown. This fully removes both paths. - If the extension is required, impose a strict maximum input length before conversion. Because the cost is quadratic, the cap must be small to meaningfully bound worst-case CPU time.
The attributes/allow allow-list added in 2.7.0 is not a mitigation. A non-empty allow-list happens to bound the first path, because unlisted names are discarded before they accumulate, but it does nothing for the second: continuation lines are merged while parsing, before any filtering takes place.
Restricting conversion to trusted users, applying strict execution-time limits, and rate-limiting requests reduce exposure but are not substitutes for upgrading.
{
"affected": [
{
"package": {
"ecosystem": "Packagist",
"name": "league/commonmark"
},
"ranges": [
{
"events": [
{
"introduced": "1.5.0"
},
{
"fixed": "2.10.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [],
"database_specific": {
"cwe_ids": [
"CWE-1050",
"CWE-407"
],
"github_reviewed": true,
"github_reviewed_at": "2026-09-01T20:28:40Z",
"nvd_published_at": null,
"severity": "HIGH"
},
"details": "### Impact\n\n`AttributesExtension` ships with the library but must be explicitly registered on the `Environment`; it is not included in `CommonMarkConverter`, `GithubFlavoredMarkdownConverter`, or `GithubFlavoredMarkdownExtension`. **Applications that do not register `AttributesExtension` are not affected by this advisory.**\n\nTwo paths in the extension re-process every attribute a node has already collected each time another attribute is applied to it. When the attributes carry distinct names, the collected set grows by one on every step and is walked again in full, so a run of *n* attributes costs O(n\u00b2).\n\n**1. Attribute nodes resolving to a common target (affected from 1.5.0).**\n\n`AttributesListener::processDocument()` merges each attribute node into the set accumulated for its target, then filters the result. Both operations traverse that entire set: `AttributesHelper::mergeAttributes()` rebuilds it with `array_merge()`, and `AttributesHelper::filterAttributes()` matches a regular expression against every name in it. A run of attribute nodes sharing one target therefore re-walks a set that grows by a key per node.\n\nTwo input shapes reach this path: adjacent inline attributes at the start of a block (`{a0=\"v\"}{a1=\"v\"}\u2026`, where quoting the values is what keeps them separate \u2014 an unquoted value swallows the `}{` that follows it), and a chain of attribute blocks held at their default target by reference definitions (`{a0=v}` / `[a]: u` / `{a1=v}` / `[a]: u` / \u2026).\n\n256 KB of adjacent inline attributes takes 20.0 seconds to convert, against 0.09 seconds once patched.\n\n**2. Consecutive attribute-block lines (affected from 2.0.0).**\n\n`AttributesBlockContinueParser::tryContinue()` merges each continuation line into the block\u0027s accumulated attributes, again rebuilding the whole set on every line. One distinct attribute per line (`{a0=v}` / `{a1=v}` / \u2026) grows it by a key each time.\n\n256 KB of such lines takes 1.9 seconds to convert while producing **zero bytes of output**, against 0.08 seconds once patched.\n\n**Relationship to GHSA-jjv6-8j6v-6j52.** The fix released in 2.9.1 for that advisory made the `class` attribute cheap to accumulate, but left every other attribute name on the original path. **Applications that upgraded to 2.9.1 or 2.9.2 remain exposed to this variant.**\n\n**Overall impact.** An unauthenticated attacker who can submit Markdown to an affected application can consume disproportionate CPU time with a comparatively small request, occupying PHP workers and preventing legitimate requests from completing. The impact is limited to availability: no data is disclosed, rendered output is unchanged, and no rendering restriction is bypassed.\n\n### Patches\n\nThe issue is patched in `2.10.0`. Both paths now fold each node \u2014 or each line \u2014 into the accumulated attributes at a cost proportional to that node or line alone, rather than re-merging and re-filtering everything gathered so far. Rendered output is unchanged, down to the order in which attributes appear.\n\nThe listener path affects `1.5.0` through `2.9.2`. The continuation-line path affects `2.0.0` through `2.9.2`. The 1.x release line is no longer supported, so its users must upgrade to `2.10.0` or later.\n\n### Workarounds\n\nIf you cannot upgrade immediately:\n\n- **Do not register `AttributesExtension`** when converting untrusted Markdown. This fully removes both paths.\n- If the extension is required, **impose a strict maximum input length before conversion**. Because the cost is quadratic, the cap must be small to meaningfully bound worst-case CPU time.\n\nThe `attributes/allow` allow-list added in 2.7.0 is **not** a mitigation. A non-empty allow-list happens to bound the first path, because unlisted names are discarded before they accumulate, but it does nothing for the second: continuation lines are merged while parsing, before any filtering takes place.\n\nRestricting conversion to trusted users, applying strict execution-time limits, and rate-limiting requests reduce exposure but are not substitutes for upgrading.",
"id": "GHSA-8rr7-cvq3-gmfh",
"modified": "2026-09-01T20:28:40Z",
"published": "2026-09-01T20:28:40Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/thephpleague/commonmark/security/advisories/GHSA-8rr7-cvq3-gmfh"
},
{
"type": "WEB",
"url": "https://github.com/thephpleague/commonmark/commit/f27eb720972490b5af4dbb635ad8634529faf9f2"
},
{
"type": "PACKAGE",
"url": "https://github.com/thephpleague/commonmark"
},
{
"type": "WEB",
"url": "https://github.com/thephpleague/commonmark/releases/tag/2.10.0"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
],
"summary": "league/commonmark: Denial of service via distinctly-named attributes in the Attributes extension"
}
GHSA-96HV-2XVQ-FX4P
Vulnerability from github – Published: 2026-06-15 16:34 – Updated: 2026-07-13 15:31Impact
A high volume of exceptionally small fragments and data chunks can be sent by a peer, with modest network traffic, to force the remote peer into allocating and holding structural wrappers that consume far more memory than the default documented message-size limit, leading to process termination due to OOM.
Proof of concept
import { WebSocket, WebSocketServer } from 'ws';
const wss = new WebSocketServer({ port: 0 }, function () {
const data = Buffer.alloc(1);
const options = { fin: false };
const { port } = wss.address();
const ws = new WebSocket(`ws://localhost:${port}`);
ws.on('open', function () {
(function send() {
ws.send(data, options, function (err) {
if (err) return;
send();
});
})();
});
ws.on('error', console.error);
ws.on('close', function (code, reason) {
console.log(`client close - code: ${code} reason: ${reason.toString()}`);
});
});
wss.on('connection', function (ws) {
ws.on('error', console.error);
ws.on('close', function (code, reason) {
console.log(`server close - code: ${code} reason: ${reason.toString()}`);
});
});
Patches
The vulnerability was fixed in ws@8.21.0 (https://github.com/websockets/ws/commit/bca91adf15677e47dbe4f959653452727be28b94) and backported to ws@7.5.11 (https://github.com/websockets/ws/commit/fd36cd864fcdf62a08273a99e19a7d975401fee8), ws@6.2.4 (https://github.com/websockets/ws/commit/86d3e8a5fb0246ed373860c5fbb0de88824a27f7), and ws@5.2.5 (https://github.com/websockets/ws/commit/b5372ac67bb97a773727b8e9f5035a8123556d53).
Workarounds
In vulnerable versions, the issue can be mitigated by lowering the value of the maxPayload option if possible.
Credits
The vulnerability was responsibly disclosed and fixed by Nadav Magier.
{
"affected": [
{
"package": {
"ecosystem": "npm",
"name": "ws"
},
"ranges": [
{
"events": [
{
"introduced": "1.1.0"
},
{
"fixed": "5.2.5"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "npm",
"name": "ws"
},
"ranges": [
{
"events": [
{
"introduced": "6.0.0"
},
{
"fixed": "6.2.4"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "npm",
"name": "ws"
},
"ranges": [
{
"events": [
{
"introduced": "7.0.0"
},
{
"fixed": "7.5.11"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "npm",
"name": "ws"
},
"ranges": [
{
"events": [
{
"introduced": "8.0.0"
},
{
"fixed": "8.21.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-48779"
],
"database_specific": {
"cwe_ids": [
"CWE-1050",
"CWE-400",
"CWE-770"
],
"github_reviewed": true,
"github_reviewed_at": "2026-06-15T16:34:23Z",
"nvd_published_at": "2026-06-17T13:20:42Z",
"severity": "HIGH"
},
"details": "### Impact\n\nA high volume of exceptionally small fragments and data chunks can be sent by a peer, with modest network traffic, to force the remote peer into allocating and holding structural wrappers that consume far more memory than the default documented message-size limit, leading to process termination due to OOM.\n\n### Proof of concept\n\n```js\nimport { WebSocket, WebSocketServer } from \u0027ws\u0027;\n\nconst wss = new WebSocketServer({ port: 0 }, function () {\n const data = Buffer.alloc(1);\n const options = { fin: false };\n const { port } = wss.address();\n const ws = new WebSocket(`ws://localhost:${port}`);\n\n ws.on(\u0027open\u0027, function () {\n (function send() {\n ws.send(data, options, function (err) {\n if (err) return;\n send();\n });\n })();\n });\n\n ws.on(\u0027error\u0027, console.error);\n ws.on(\u0027close\u0027, function (code, reason) {\n console.log(`client close - code: ${code} reason: ${reason.toString()}`);\n });\n});\n\nwss.on(\u0027connection\u0027, function (ws) {\n ws.on(\u0027error\u0027, console.error);\n ws.on(\u0027close\u0027, function (code, reason) {\n console.log(`server close - code: ${code} reason: ${reason.toString()}`);\n });\n});\n```\n\n### Patches\n\nThe vulnerability was fixed in ws@8.21.0 (https://github.com/websockets/ws/commit/bca91adf15677e47dbe4f959653452727be28b94) and backported to ws@7.5.11 (https://github.com/websockets/ws/commit/fd36cd864fcdf62a08273a99e19a7d975401fee8), ws@6.2.4 (https://github.com/websockets/ws/commit/86d3e8a5fb0246ed373860c5fbb0de88824a27f7), and ws@5.2.5 (https://github.com/websockets/ws/commit/b5372ac67bb97a773727b8e9f5035a8123556d53).\n\n### Workarounds\n\nIn vulnerable versions, the issue can be mitigated by lowering the value of the `maxPayload` option if possible.\n\n### Credits\n\nThe vulnerability was responsibly disclosed and fixed by [Nadav Magier](https://github.com/Nadav0077).",
"id": "GHSA-96hv-2xvq-fx4p",
"modified": "2026-07-13T15:31:39Z",
"published": "2026-06-15T16:34:23Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/websockets/ws/security/advisories/GHSA-96hv-2xvq-fx4p"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-48779"
},
{
"type": "WEB",
"url": "https://github.com/websockets/ws/commit/fd36cd864fcdf62a08273a99e19a7d975401fee8"
},
{
"type": "WEB",
"url": "https://github.com/websockets/ws/commit/bca91adf15677e47dbe4f959653452727be28b94"
},
{
"type": "WEB",
"url": "https://github.com/websockets/ws/commit/b5372ac67bb97a773727b8e9f5035a8123556d53"
},
{
"type": "WEB",
"url": "https://github.com/websockets/ws/commit/86d3e8a5fb0246ed373860c5fbb0de88824a27f7"
},
{
"type": "WEB",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-48779.json"
},
{
"type": "PACKAGE",
"url": "https://github.com/websockets/ws"
},
{
"type": "WEB",
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2489661"
},
{
"type": "WEB",
"url": "https://access.redhat.com/security/cve/CVE-2026-48779"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2026:37272"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2026:36820"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2026:36754"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2026:34342"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2026:33574"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2026:33183"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2026:33173"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2026:33163"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2026:33160"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2026:33155"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2026:29197"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2026:27171"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2026:26638"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
],
"summary": "ws: Memory exhaustion DoS from tiny fragments and data chunks"
}
GHSA-GGH5-2M6X-59XG
Vulnerability from github – Published: 2026-09-28 09:30 – Updated: 2026-09-28 09:30A denial of service via unsigned underflow in libXpm's write path in libXpm before 3.5.19 could be used by local attackers to cause unbounded CPU usage and memory exhaustion.
{
"affected": [],
"aliases": [
"CVE-2026-94287"
],
"database_specific": {
"cwe_ids": [
"CWE-1050"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-09-28T09:17:08Z",
"severity": "MODERATE"
},
"details": "A denial of service via unsigned underflow in libXpm\u0027s write path in libXpm before 3.5.19 could be used by local attackers to cause unbounded CPU usage and memory exhaustion.",
"id": "GHSA-ggh5-2m6x-59xg",
"modified": "2026-09-28T09:30:32Z",
"published": "2026-09-28T09:30:32Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-94287"
},
{
"type": "WEB",
"url": "https://gitlab.freedesktop.org/xorg/lib/libxpm/-/merge_requests/32/diffs?commit_id=3a68f818b1628d7ad96245b0f4d15a32a015b0ab"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-GRV7-FG5C-XMJG
Vulnerability from github – Published: 2024-05-14 18:30 – Updated: 2024-06-10 20:17The NPM package braces fails to limit the number of characters it can handle, which could lead to Memory Exhaustion. In lib/parse.js, if a malicious user sends "imbalanced braces" as input, the parsing will enter a loop, which will cause the program to start allocating heap memory without freeing it at any moment of the loop. Eventually, the JavaScript heap limit is reached, and the program will crash.
{
"affected": [
{
"package": {
"ecosystem": "npm",
"name": "braces"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "3.0.3"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2024-4068"
],
"database_specific": {
"cwe_ids": [
"CWE-1050",
"CWE-400"
],
"github_reviewed": true,
"github_reviewed_at": "2024-06-10T20:17:26Z",
"nvd_published_at": "2024-05-14T15:42:48Z",
"severity": "HIGH"
},
"details": "The NPM package `braces` fails to limit the number of characters it can handle, which could lead to Memory Exhaustion. In `lib/parse.js,` if a malicious user sends \"imbalanced braces\" as input, the parsing will enter a loop, which will cause the program to start allocating heap memory without freeing it at any moment of the loop. Eventually, the JavaScript heap limit is reached, and the program will crash.\n",
"id": "GHSA-grv7-fg5c-xmjg",
"modified": "2024-06-10T20:17:26Z",
"published": "2024-05-14T18:30:54Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-4068"
},
{
"type": "WEB",
"url": "https://github.com/micromatch/braces/issues/35"
},
{
"type": "WEB",
"url": "https://github.com/micromatch/braces/pull/37"
},
{
"type": "WEB",
"url": "https://github.com/micromatch/braces/pull/40"
},
{
"type": "WEB",
"url": "https://github.com/micromatch/braces/commit/415d660c3002d1ab7e63dbf490c9851da80596ff"
},
{
"type": "WEB",
"url": "https://devhub.checkmarx.com/cve-details/CVE-2024-4068"
},
{
"type": "PACKAGE",
"url": "https://github.com/micromatch/braces"
},
{
"type": "WEB",
"url": "https://github.com/micromatch/braces/blob/98414f9f1fabe021736e26836d8306d5de747e0d/lib/parse.js#L308"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
],
"summary": "Uncontrolled resource consumption in braces"
}
GHSA-H4WV-G838-66G3
Vulnerability from github – Published: 2026-04-02 15:31 – Updated: 2026-04-04 06:00A flaw was found in Keycloak. An unauthenticated attacker can exploit this vulnerability by sending a specially crafted POST request with an excessively long scope parameter to the OpenID Connect (OIDC) token endpoint. This leads to high resource consumption and prolonged processing times, ultimately resulting in a Denial of Service (DoS) for the Keycloak server.
{
"affected": [
{
"package": {
"ecosystem": "Maven",
"name": "org.keycloak:keycloak-services"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "26.5.7"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-4634"
],
"database_specific": {
"cwe_ids": [
"CWE-1050"
],
"github_reviewed": true,
"github_reviewed_at": "2026-04-04T06:00:47Z",
"nvd_published_at": "2026-04-02T13:16:27Z",
"severity": "HIGH"
},
"details": "A flaw was found in Keycloak. An unauthenticated attacker can exploit this vulnerability by sending a specially crafted POST request with an excessively long scope parameter to the OpenID Connect (OIDC) token endpoint. This leads to high resource consumption and prolonged processing times, ultimately resulting in a Denial of Service (DoS) for the Keycloak server.",
"id": "GHSA-h4wv-g838-66g3",
"modified": "2026-04-04T06:00:47Z",
"published": "2026-04-02T15:31:39Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-4634"
},
{
"type": "WEB",
"url": "https://github.com/keycloak/keycloak/issues/47716"
},
{
"type": "WEB",
"url": "https://github.com/keycloak/keycloak/commit/b455ee4f28abb6f2120aff72fd179589cc5267a0"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2026:6475"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2026:6476"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2026:6477"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2026:6478"
},
{
"type": "WEB",
"url": "https://access.redhat.com/security/cve/CVE-2026-4634"
},
{
"type": "WEB",
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2450250"
},
{
"type": "PACKAGE",
"url": "https://github.com/keycloak/keycloak"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
],
"summary": "Keycloak: Application-Level DoS via Scope Processing"
}
GHSA-HJMX-QF9H-V7MW
Vulnerability from github – Published: 2026-09-16 15:31 – Updated: 2026-09-16 15:31If a BIND resolver has cached a tree of SVCB/HTTPS AliasMode records, and is then queried for the root of that tree, the resolver will spend disproportionate CPU time constructing the response. This issue affects BIND 9 versions 9.18.0 through 9.18.50, 9.20.0 through 9.20.27, 9.21.0 through 9.21.25, 9.18.11-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.27-S1.
{
"affected": [],
"aliases": [
"CVE-2026-81736"
],
"database_specific": {
"cwe_ids": [
"CWE-1050"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-09-16T14:17:10Z",
"severity": "HIGH"
},
"details": "If a BIND resolver has cached a tree of SVCB/HTTPS AliasMode records, and is then queried for the root of that tree, the resolver will spend disproportionate CPU time constructing the response.\nThis issue affects BIND 9 versions 9.18.0 through 9.18.50, 9.20.0 through 9.20.27, 9.21.0 through 9.21.25, 9.18.11-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.27-S1.",
"id": "GHSA-hjmx-qf9h-v7mw",
"modified": "2026-09-16T15:31:10Z",
"published": "2026-09-16T15:31:10Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-81736"
},
{
"type": "WEB",
"url": "https://downloads.isc.org/isc/bind9/9.20.29"
},
{
"type": "WEB",
"url": "https://downloads.isc.org/isc/bind9/9.21.26"
},
{
"type": "WEB",
"url": "https://kb.isc.org/docs/cve-2026-81736"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-J8PM-GJ4C-RQ4X
Vulnerability from github – Published: 2026-09-01 20:17 – Updated: 2026-09-01 20:17Impact
Affected versions of league/commonmark perform super-linear work on three independent parsing paths, all of which are reachable on a stock new CommonMarkConverter() with default configuration and no extensions registered. Each trigger fits on a single line of input, so no complex Markdown structure is required.
The three paths were introduced at different times. This advisory's version range is their union; the individual ranges are:
| Path | Affected from | Affected through |
|---|---|---|
| 1. Fenced code block detection | 0.6.0 |
2.9.0 |
| 2. Reference link label lookup | 0.6.0 |
2.9.0 |
3. Emphasis / strikethrough delimiters (*, _, ~) |
2.6.0 |
2.9.0 |
3. Highlight delimiters (=) |
2.9.0 |
2.9.0 |
1. Fenced code block detection — quadratic, affected from 0.6.0.
FencedCodeStartParser matches the following pattern:
/^[ \t]*(?:`{3,}(?!.*`)|~{3,})/
The lookahead enforces the CommonMark rule that a backtick fence's info string may not itself contain a backtick, but neither the lookahead nor the backtick run it guards is atomic or possessive. On a line consisting of a long backtick run, filler text, and a single trailing backtick, the quantifier gives back one character at a time and re-runs the lookahead across the remainder of the line on every candidate fence length.
A 320 KB single line takes roughly 27 seconds to convert. The identical payload with one x character prefixed — which fails the parser's own leading-character guard — takes 0.011 seconds. preg_last_error() returns 0 at every input size tested, including runs of 160,000 characters, so PCRE never reaches pcre.backtrack_limit and this is sustained CPU consumption rather than an early bail-out.
2. Reference link label lookup — effectively quadratic, affected from 0.6.0.
When a shortcut or collapsed reference link is attempted, CloseBracketParser::tryParseReference() copies the entire span between the brackets and passes it to ReferenceMap::get(), which normalizes the label — up to four full passes over its length (trim, preg_replace, mb_check_encoding, and strtolower, or mb_convert_case on the non-ASCII path). Nested brackets produce one such lookup per closing bracket, each on a span two characters longer than the last.
In 2.x the normalization sits behind an early return for an empty reference map, so a single 8-byte reference definition anywhere in the document ([x]: y) is enough to unlock the path. At n = 64,000 nested brackets the same input takes 22.0 seconds with that line present versus 0.59 seconds without it. A single non-ASCII character inside the brackets forces the mb_convert_case branch, costing roughly 2.5x more again.
3. Emphasis, strikethrough, and highlight delimiter processing — super-linear, affected from 2.6.0.
DelimiterStack::processDelimiters() remains linear only because of the openersBottom memo, which bounds the backward opener scan — an argument that holds only if the memo's key space is O(1). EmphasisDelimiterProcessor::getCacheKey(), and the equivalents in StrikethroughDelimiterProcessor and MarkDelimiterProcessor, embed the closer's raw current run length in the key, leaving that space unbounded. An attacker spends O(n) bytes minting a growing number of distinct run lengths; each distinct length is a fresh key whose recorded bound starts at zero, forcing a full backward re-scan of the entire pile of openers.
The resulting work grows as roughly n^1.5. This is sub-quadratic, but the amplification over linear growth itself scales with input size, so it worsens as inputs grow: 800 KB of ordinary asterisks, letters, and spaces costs roughly 27 seconds on a stock converter.
This path is a regression introduced in 2.6.0. Before that release the cache key was the bare delimiter character — a bounded key space that amortized correctly. * and _ are affected on any default configuration from 2.6.0 onward. ~ (StrikethroughExtension, included in GithubFlavoredMarkdownConverter and GithubFlavoredMarkdownExtension) is affected from 2.6.0. = (HighlightExtension) is affected only from 2.9.0, when MarkDelimiterProcessor was declared cacheable.
Overall impact. An unauthenticated attacker who can submit Markdown for conversion can use a comparatively small request to consume disproportionate CPU time. Repeated or concurrent requests can occupy all available PHP workers and prevent legitimate requests from completing. The impact is limited to availability: no data is disclosed, rendered output is unchanged, and no rendering restriction is bypassed. Applications that process only trusted Markdown are not remotely exploitable.
Settings such as html_input, allow_unsafe_links, and max_nesting_level do not mitigate any of these, because the expensive work occurs during parsing, before rendering. max_delimiters_per_line bounds the third path only, and does so lossily — it silently discards emphasis once the cap is exhausted.
Patches
The issues are patched in 2.9.1 and later:
- The fenced code block quantifier is now possessive, which is behavior-identical here: any character given back moves a backtick into the lookahead's scan range, so every retry was guaranteed to fail regardless.
- Reference link lookups now apply the CommonMark 999-character link label limit before copying and normalizing the label, matching the limit already enforced when parsing reference definitions. Because a definition can never exceed that length, an over-length lookup label cannot match one directly. One edge case does change: a label longer than 999 characters that collapses to a shorter match once whitespace is normalized — for example
[afollowed by 998 spaces andb]against a[a b]: /urldefinition — previously rendered as a link and now renders literally. This follows cmark, which applies its own label-length cap before normalizing (cmark_reference_lookup()), and matches how this library has always handled the equivalent[text][label]form viaLinkParserHelper::parseLinkLabel(). commonmark.js normalizes first and still resolves such labels. - Delimiter processor cache keys now clamp the run length to the coarsest bucket that can change behavior —
min(length, 2)for emphasis,min(length, 3)for strikethrough and highlight — restoring a bounded key space while preserving byte-identical output.
Versions from 0.6.0 through 2.9.0 are affected by at least one of these paths; see the table above for which paths apply to which releases. The 0.x and 1.x release lines are no longer supported, so their users must upgrade to 2.9.1 or later.
Workarounds
If you cannot upgrade immediately, enforce a maximum length for individual lines before passing input to the converter, in addition to a total request-size limit. A per-line limit matters because every trigger described above fits within a single line. Because the cost grows super-linearly, the cap must be genuinely small to bound worst-case CPU.
Setting max_delimiters_per_line reduces exposure to the delimiter path only, and does so by silently dropping emphasis from the rendered output. It has no effect on the fenced code or reference link paths.
Restricting conversion to trusted users, applying strict execution-time limits, rate-limiting requests, and limiting concurrent conversions all reduce exposure, but none is a complete substitute for upgrading.
{
"affected": [
{
"package": {
"ecosystem": "Packagist",
"name": "league/commonmark"
},
"ranges": [
{
"events": [
{
"introduced": "0.6.0"
},
{
"fixed": "2.9.1"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [],
"database_specific": {
"cwe_ids": [
"CWE-1050",
"CWE-1333",
"CWE-407"
],
"github_reviewed": true,
"github_reviewed_at": "2026-09-01T20:17:59Z",
"nvd_published_at": null,
"severity": "HIGH"
},
"details": "### Impact\n\nAffected versions of `league/commonmark` perform super-linear work on three independent parsing paths, all of which are reachable on a stock `new CommonMarkConverter()` with default configuration and no extensions registered. Each trigger fits on a single line of input, so no complex Markdown structure is required.\n\nThe three paths were introduced at different times. This advisory\u0027s version range is their union; the individual ranges are:\n\n| Path | Affected from | Affected through |\n|---|---|---|\n| 1. Fenced code block detection | `0.6.0` | `2.9.0` |\n| 2. Reference link label lookup | `0.6.0` | `2.9.0` |\n| 3. Emphasis / strikethrough delimiters (`*`, `_`, `~`) | `2.6.0` | `2.9.0` |\n| 3. Highlight delimiters (`=`) | `2.9.0` | `2.9.0` |\n\n**1. Fenced code block detection \u2014 quadratic, affected from 0.6.0.**\n\n`FencedCodeStartParser` matches the following pattern:\n\n```\n/^[ \\t]*(?:`{3,}(?!.*`)|~{3,})/\n```\n\nThe lookahead enforces the CommonMark rule that a backtick fence\u0027s info string may not itself contain a backtick, but neither the lookahead nor the backtick run it guards is atomic or possessive. On a line consisting of a long backtick run, filler text, and a single trailing backtick, the quantifier gives back one character at a time and re-runs the lookahead across the remainder of the line on every candidate fence length.\n\nA 320 KB single line takes roughly 27 seconds to convert. The identical payload with one `x` character prefixed \u2014 which fails the parser\u0027s own leading-character guard \u2014 takes 0.011 seconds. `preg_last_error()` returns `0` at every input size tested, including runs of 160,000 characters, so PCRE never reaches `pcre.backtrack_limit` and this is sustained CPU consumption rather than an early bail-out.\n\n**2. Reference link label lookup \u2014 effectively quadratic, affected from 0.6.0.**\n\nWhen a shortcut or collapsed reference link is attempted, `CloseBracketParser::tryParseReference()` copies the entire span between the brackets and passes it to `ReferenceMap::get()`, which normalizes the label \u2014 up to four full passes over its length (`trim`, `preg_replace`, `mb_check_encoding`, and `strtolower`, or `mb_convert_case` on the non-ASCII path). Nested brackets produce one such lookup per closing bracket, each on a span two characters longer than the last.\n\nIn 2.x the normalization sits behind an early return for an empty reference map, so a single 8-byte reference definition anywhere in the document (`[x]: y`) is enough to unlock the path. At n = 64,000 nested brackets the same input takes 22.0 seconds with that line present versus 0.59 seconds without it. A single non-ASCII character inside the brackets forces the `mb_convert_case` branch, costing roughly 2.5x more again.\n\n**3. Emphasis, strikethrough, and highlight delimiter processing \u2014 super-linear, affected from 2.6.0.**\n\n`DelimiterStack::processDelimiters()` remains linear only because of the `openersBottom` memo, which bounds the backward opener scan \u2014 an argument that holds only if the memo\u0027s key space is O(1). `EmphasisDelimiterProcessor::getCacheKey()`, and the equivalents in `StrikethroughDelimiterProcessor` and `MarkDelimiterProcessor`, embed the closer\u0027s raw current run length in the key, leaving that space unbounded. An attacker spends O(n) bytes minting a growing number of distinct run lengths; each distinct length is a fresh key whose recorded bound starts at zero, forcing a full backward re-scan of the entire pile of openers.\n\nThe resulting work grows as roughly n^1.5. This is sub-quadratic, but the amplification over linear growth itself scales with input size, so it worsens as inputs grow: 800 KB of ordinary asterisks, letters, and spaces costs roughly 27 seconds on a stock converter.\n\nThis path is a regression introduced in **2.6.0**. Before that release the cache key was the bare delimiter character \u2014 a bounded key space that amortized correctly. `*` and `_` are affected on any default configuration from 2.6.0 onward. `~` (`StrikethroughExtension`, included in `GithubFlavoredMarkdownConverter` and `GithubFlavoredMarkdownExtension`) is affected from 2.6.0. `=` (`HighlightExtension`) is affected only from **2.9.0**, when `MarkDelimiterProcessor` was declared cacheable.\n\n**Overall impact.** An unauthenticated attacker who can submit Markdown for conversion can use a comparatively small request to consume disproportionate CPU time. Repeated or concurrent requests can occupy all available PHP workers and prevent legitimate requests from completing. The impact is limited to availability: no data is disclosed, rendered output is unchanged, and no rendering restriction is bypassed. Applications that process only trusted Markdown are not remotely exploitable.\n\nSettings such as `html_input`, `allow_unsafe_links`, and `max_nesting_level` do not mitigate any of these, because the expensive work occurs during parsing, before rendering. `max_delimiters_per_line` bounds the third path only, and does so lossily \u2014 it silently discards emphasis once the cap is exhausted.\n\n### Patches\n\nThe issues are patched in `2.9.1` and later:\n\n- The fenced code block quantifier is now possessive, which is behavior-identical here: any character given back moves a backtick into the lookahead\u0027s scan range, so every retry was guaranteed to fail regardless.\n- Reference link *lookups* now apply the CommonMark 999-character link label limit before copying and normalizing the label, matching the limit already enforced when parsing reference *definitions*. Because a definition can never exceed that length, an over-length lookup label cannot match one directly. One edge case does change: a label longer than 999 characters that *collapses* to a shorter match once whitespace is normalized \u2014 for example `[a` followed by 998 spaces and `b]` against a `[a b]: /url` definition \u2014 previously rendered as a link and now renders literally. This follows cmark, which applies its own label-length cap before normalizing (`cmark_reference_lookup()`), and matches how this library has always handled the equivalent `[text][label]` form via `LinkParserHelper::parseLinkLabel()`. commonmark.js normalizes first and still resolves such labels.\n- Delimiter processor cache keys now clamp the run length to the coarsest bucket that can change behavior \u2014 `min(length, 2)` for emphasis, `min(length, 3)` for strikethrough and highlight \u2014 restoring a bounded key space while preserving byte-identical output.\n\nVersions from `0.6.0` through `2.9.0` are affected by at least one of these paths; see the table above for which paths apply to which releases. The 0.x and 1.x release lines are no longer supported, so their users must upgrade to `2.9.1` or later.\n\n### Workarounds\n\nIf you cannot upgrade immediately, enforce a **maximum length for individual lines** before passing input to the converter, in addition to a total request-size limit. A per-line limit matters because every trigger described above fits within a single line. Because the cost grows super-linearly, the cap must be genuinely small to bound worst-case CPU.\n\nSetting `max_delimiters_per_line` reduces exposure to the delimiter path only, and does so by silently dropping emphasis from the rendered output. It has no effect on the fenced code or reference link paths.\n\nRestricting conversion to trusted users, applying strict execution-time limits, rate-limiting requests, and limiting concurrent conversions all reduce exposure, but none is a complete substitute for upgrading.",
"id": "GHSA-j8pm-gj4c-rq4x",
"modified": "2026-09-01T20:17:59Z",
"published": "2026-09-01T20:17:59Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/thephpleague/commonmark/security/advisories/GHSA-j8pm-gj4c-rq4x"
},
{
"type": "WEB",
"url": "https://github.com/thephpleague/commonmark/commit/0768217751fbfaeb8d76762f6944e9af7114295e"
},
{
"type": "WEB",
"url": "https://github.com/thephpleague/commonmark/commit/d9375fadc308a63a02950a68d822417a6e4c33b2"
},
{
"type": "WEB",
"url": "https://github.com/thephpleague/commonmark/commit/e0036ef031fd36ec1c3c82db8743fc928b5271c8"
},
{
"type": "PACKAGE",
"url": "https://github.com/thephpleague/commonmark"
},
{
"type": "WEB",
"url": "https://github.com/thephpleague/commonmark/releases/tag/2.9.1"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
],
"summary": "league/commonmark: Denial of service via crafted code fences, reference links, and emphasis delimiters"
}
GHSA-JJV6-8J6V-6J52
Vulnerability from github – Published: 2026-09-01 20:21 – Updated: 2026-09-01 20:21Impact
Two first-party extensions contain quadratic parsing paths. Both ship with the library but must be explicitly registered on the Environment; neither is included in CommonMarkConverter, GithubFlavoredMarkdownConverter, or GithubFlavoredMarkdownExtension. Applications that do not register SmartPunctExtension or AttributesExtension are not affected by this advisory.
1. SmartPunctExtension — quote replacement recopies the whole text node (affected from 2.0.0).
ReplaceUnpairedQuotesListener converts each unpaired Quote node back to a Text node and merges it into its neighbours via AdjacentTextMerger. The merge reads the left node's literal into a local variable, appends to that variable, and writes it back — and because the read aliases the node's string, every append copies the entire accumulated literal rather than only the bytes added. The listener runs this once per surviving unpaired quote against the same continuously growing text node, so the same buffer is fully re-copied a linear number of times.
A 1.2 MB document of alternating text segments and apostrophes takes 34.9 seconds to convert, against 0.069 seconds for the same input with the extension not registered.
Hardened configuration makes this worse rather than better: QuoteParser appends the Quote node to the AST before pushing it onto the delimiter stack, so max_delimiters_per_line removes the quote-pairing work while leaving every node the listener must process.
2. AttributesExtension — block-level attribute runs re-scan their siblings (affected from 1.5.0).
AttributesListener::findTargetAndDirection() walks the entire remaining sibling chain for every block-level Attributes node whose target is the following node. The backward half of that walk returns immediately for such nodes, and the forward half stops only at a sibling that is not itself an attributes node — which a contiguous run never provides — so a run of k nodes costs k(k-1)/2 steps.
An input placing each {#a} on its own line, with a single reference definition to keep the run contiguous, takes 28.4 seconds at 16,000 attribute blocks while producing zero bytes of output.
This is the block-level counterpart of GHSA-g2gp-3wwq-f4ph, patched in 2.9.0. That fix is incomplete: the early break it introduced is guarded on the node being an AttributesInline, so block-level Attributes nodes still re-scan. Applications that upgraded to 2.9.0 specifically to address GHSA-g2gp-3wwq-f4ph remain exposed to this variant.
3. AttributesExtension — class lists are rebuilt on every merge (affected from 1.5.0).
AttributesHelper::mergeAttributes() round-trips the accumulated class list through explode and implode on each merge. An #id attribute assigns a scalar and skips the branch entirely, but a .class attribute appends to an array which is then imploded to a string, written to the target node, and read back on the next iteration — so the ith merge pays a cost proportional to i three separate times.
{.c} repeated 32,000 times takes 33.5 seconds, against 0.26 seconds for byte-identical input using {#a} — a 130x gap that widens with input size. Both the inline and the block-level attribute paths are affected.
Overall impact. An unauthenticated attacker who can submit Markdown to an affected application can consume disproportionate CPU time with a comparatively small request, occupying PHP workers and preventing legitimate requests from completing. The impact is limited to availability: no data is disclosed, rendered output is unchanged, and no rendering restriction is bypassed.
No library-level configuration gates any of these paths. For the Attributes extension in particular, neither the attributes/allow allow-list nor the on* event-handler hardening added in 2.7.0 has any effect, because the expensive work happens while parsing and resolving the AST, before any attribute filtering or rendering takes place.
Patches
The issues are patched in 2.9.1 and later:
- Adjacent text merging now appends in place instead of reading, modifying, and writing back the whole literal, so a merge costs only the bytes added. This fixes the defect for every caller, not only the SmartPunct listener.
AttributesListenernow records the runs it has already walked, so each contiguous run of block-level attribute nodes is scanned once rather than once per node.- Accumulated class lists no longer pass through
mergeAttributes()repeatedly; the listener holds pending attributes and joins them in a single pass.
The SmartPunct path affects 2.0.0 through 2.9.0. The Attributes paths affect 1.5.0 through 2.9.0, including releases that already contain the 2.9.0 fix for GHSA-g2gp-3wwq-f4ph. The 1.x release line is no longer supported, so its users must upgrade to 2.9.1 or later.
Workarounds
If you cannot upgrade immediately:
- Do not register
SmartPunctExtensionorAttributesExtensionwhen converting untrusted Markdown. This fully removes the affected paths. - If either extension is required, impose a strict maximum input length before conversion. Because the cost is quadratic, even a modest cap must be small to meaningfully bound worst-case CPU time.
Restricting conversion to trusted users, applying strict execution-time limits, and rate-limiting requests reduce exposure but are not substitutes for upgrading. Configuration options including attributes/allow, max_delimiters_per_line, max_nesting_level, html_input, and allow_unsafe_links do not mitigate these issues.
{
"affected": [
{
"package": {
"ecosystem": "Packagist",
"name": "league/commonmark"
},
"ranges": [
{
"events": [
{
"introduced": "1.5.0"
},
{
"fixed": "2.9.1"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [],
"database_specific": {
"cwe_ids": [
"CWE-1050",
"CWE-407"
],
"github_reviewed": true,
"github_reviewed_at": "2026-09-01T20:21:45Z",
"nvd_published_at": null,
"severity": "HIGH"
},
"details": "### Impact\n\nTwo first-party extensions contain quadratic parsing paths. Both ship with the library but must be explicitly registered on the `Environment`; neither is included in `CommonMarkConverter`, `GithubFlavoredMarkdownConverter`, or `GithubFlavoredMarkdownExtension`. **Applications that do not register `SmartPunctExtension` or `AttributesExtension` are not affected by this advisory.**\n\n**1. `SmartPunctExtension` \u2014 quote replacement recopies the whole text node (affected from 2.0.0).**\n\n`ReplaceUnpairedQuotesListener` converts each unpaired `Quote` node back to a `Text` node and merges it into its neighbours via `AdjacentTextMerger`. The merge reads the left node\u0027s literal into a local variable, appends to that variable, and writes it back \u2014 and because the read aliases the node\u0027s string, every append copies the entire accumulated literal rather than only the bytes added. The listener runs this once per surviving unpaired quote against the same continuously growing text node, so the same buffer is fully re-copied a linear number of times.\n\nA 1.2 MB document of alternating text segments and apostrophes takes 34.9 seconds to convert, against 0.069 seconds for the same input with the extension not registered.\n\nHardened configuration makes this *worse* rather than better: `QuoteParser` appends the `Quote` node to the AST before pushing it onto the delimiter stack, so `max_delimiters_per_line` removes the quote-pairing work while leaving every node the listener must process.\n\n**2. `AttributesExtension` \u2014 block-level attribute runs re-scan their siblings (affected from 1.5.0).**\n\n`AttributesListener::findTargetAndDirection()` walks the entire remaining sibling chain for every block-level `Attributes` node whose target is the following node. The backward half of that walk returns immediately for such nodes, and the forward half stops only at a sibling that is not itself an attributes node \u2014 which a contiguous run never provides \u2014 so a run of k nodes costs k(k-1)/2 steps.\n\nAn input placing each `{#a}` on its own line, with a single reference definition to keep the run contiguous, takes 28.4 seconds at 16,000 attribute blocks while producing **zero bytes of output**.\n\nThis is the block-level counterpart of GHSA-g2gp-3wwq-f4ph, patched in 2.9.0. **That fix is incomplete:** the early break it introduced is guarded on the node being an `AttributesInline`, so block-level `Attributes` nodes still re-scan. Applications that upgraded to 2.9.0 specifically to address GHSA-g2gp-3wwq-f4ph remain exposed to this variant.\n\n**3. `AttributesExtension` \u2014 class lists are rebuilt on every merge (affected from 1.5.0).**\n\n`AttributesHelper::mergeAttributes()` round-trips the accumulated class list through `explode` and `implode` on each merge. An `#id` attribute assigns a scalar and skips the branch entirely, but a `.class` attribute appends to an array which is then imploded to a string, written to the target node, and read back on the next iteration \u2014 so the *i*th merge pays a cost proportional to *i* three separate times.\n\n`{.c}` repeated 32,000 times takes 33.5 seconds, against 0.26 seconds for byte-identical input using `{#a}` \u2014 a 130x gap that widens with input size. Both the inline and the block-level attribute paths are affected.\n\n**Overall impact.** An unauthenticated attacker who can submit Markdown to an affected application can consume disproportionate CPU time with a comparatively small request, occupying PHP workers and preventing legitimate requests from completing. The impact is limited to availability: no data is disclosed, rendered output is unchanged, and no rendering restriction is bypassed.\n\nNo library-level configuration gates any of these paths. For the Attributes extension in particular, neither the `attributes/allow` allow-list nor the `on*` event-handler hardening added in 2.7.0 has any effect, because the expensive work happens while parsing and resolving the AST, before any attribute filtering or rendering takes place.\n\n### Patches\n\nThe issues are patched in `2.9.1` and later:\n\n- Adjacent text merging now appends in place instead of reading, modifying, and writing back the whole literal, so a merge costs only the bytes added. This fixes the defect for every caller, not only the SmartPunct listener.\n- `AttributesListener` now records the runs it has already walked, so each contiguous run of block-level attribute nodes is scanned once rather than once per node.\n- Accumulated class lists no longer pass through `mergeAttributes()` repeatedly; the listener holds pending attributes and joins them in a single pass.\n\nThe SmartPunct path affects `2.0.0` through `2.9.0`. The Attributes paths affect `1.5.0` through `2.9.0`, including releases that already contain the 2.9.0 fix for GHSA-g2gp-3wwq-f4ph. The 1.x release line is no longer supported, so its users must upgrade to `2.9.1` or later.\n\n### Workarounds\n\nIf you cannot upgrade immediately:\n\n- **Do not register `SmartPunctExtension` or `AttributesExtension`** when converting untrusted Markdown. This fully removes the affected paths.\n- If either extension is required, **impose a strict maximum input length before conversion**. Because the cost is quadratic, even a modest cap must be small to meaningfully bound worst-case CPU time.\n\nRestricting conversion to trusted users, applying strict execution-time limits, and rate-limiting requests reduce exposure but are not substitutes for upgrading. Configuration options including `attributes/allow`, `max_delimiters_per_line`, `max_nesting_level`, `html_input`, and `allow_unsafe_links` do not mitigate these issues.",
"id": "GHSA-jjv6-8j6v-6j52",
"modified": "2026-09-01T20:21:45Z",
"published": "2026-09-01T20:21:45Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/thephpleague/commonmark/security/advisories/GHSA-jjv6-8j6v-6j52"
},
{
"type": "WEB",
"url": "https://github.com/thephpleague/commonmark/commit/04a5d11ef6bf2d0b927310810d6a2a85d3c184b9"
},
{
"type": "WEB",
"url": "https://github.com/thephpleague/commonmark/commit/2f611b599c51661b005dc45c16ceaa547546e687"
},
{
"type": "PACKAGE",
"url": "https://github.com/thephpleague/commonmark"
},
{
"type": "WEB",
"url": "https://github.com/thephpleague/commonmark/releases/tag/2.9.1"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
],
"summary": "league/commonmark: Denial of service in the SmartPunct and Attributes extensions"
}
GHSA-M2Q5-XHQG-92R2
Vulnerability from github – Published: 2026-01-05 21:30 – Updated: 2026-01-05 23:15A Denial of Service (DoS) vulnerability in evershop 2.1.0 and prior allows unauthenticated attackers to exhaust the application server's resources via the "GET /images" API. The application fails to limit the height of the use-element shadow tree or the dimensions of pattern tiles during the processing of SVG files, resulting in unbounded resource consumption and system-wide denial of service.
{
"affected": [
{
"package": {
"ecosystem": "npm",
"name": "@evershop/evershop"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"last_affected": "2.1.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2025-67419"
],
"database_specific": {
"cwe_ids": [
"CWE-1050"
],
"github_reviewed": true,
"github_reviewed_at": "2026-01-05T23:15:20Z",
"nvd_published_at": "2026-01-05T20:16:03Z",
"severity": "HIGH"
},
"details": "A Denial of Service (DoS) vulnerability in evershop 2.1.0 and prior allows unauthenticated attackers to exhaust the application server\u0027s resources via the \"GET /images\" API. The application fails to limit the height of the use-element shadow tree or the dimensions of pattern tiles during the processing of SVG files, resulting in unbounded resource consumption and system-wide denial of service.",
"id": "GHSA-m2q5-xhqg-92r2",
"modified": "2026-01-05T23:15:20Z",
"published": "2026-01-05T21:30:33Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-67419"
},
{
"type": "WEB",
"url": "https://github.com/dos-m0nk3y/CVE/tree/main/CVE-2025-67419"
},
{
"type": "PACKAGE",
"url": "https://github.com/evershopcommerce/evershop"
},
{
"type": "WEB",
"url": "https://pages.dos-m0nk3y.com/blog/EverShop%202.1.0%20-%20Unauthenticated%20DoS/#denial-of-service-dos-cve-2025-67419"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:P",
"type": "CVSS_V4"
}
],
"summary": "evershop allows unauthenticated attackers to exhaust application server\u0027s resources via \"GET /images\" API"
}
GHSA-WXC4-F4M6-WWQV
Vulnerability from github – Published: 2021-12-20 16:55 – Updated: 2023-02-09 17:45The Kubernetes API Server component in versions 1.1-1.14, and versions prior to 1.15.10, 1.16.7 and 1.17.3 allows an authorized user who sends malicious YAML payloads to cause the kube-apiserver to consume excessive CPU cycles while parsing YAML.
{
"affected": [
{
"package": {
"ecosystem": "Go",
"name": "gopkg.in/yaml.v2"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "2.2.8"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "Go",
"name": "github.com/go-yaml/yaml"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"last_affected": "2.1.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2019-11254"
],
"database_specific": {
"cwe_ids": [
"CWE-1050"
],
"github_reviewed": true,
"github_reviewed_at": "2021-05-07T17:24:04Z",
"nvd_published_at": null,
"severity": "MODERATE"
},
"details": "The Kubernetes API Server component in versions 1.1-1.14, and versions prior to 1.15.10, 1.16.7 and 1.17.3 allows an authorized user who sends malicious YAML payloads to cause the kube-apiserver to consume excessive CPU cycles while parsing YAML.",
"id": "GHSA-wxc4-f4m6-wwqv",
"modified": "2023-02-09T17:45:10Z",
"published": "2021-12-20T16:55:06Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2019-11254"
},
{
"type": "WEB",
"url": "https://github.com/kubernetes/kubernetes/issues/89535"
},
{
"type": "WEB",
"url": "https://github.com/go-yaml/yaml/pull/555"
},
{
"type": "WEB",
"url": "https://github.com/kubernetes/kubernetes/pull/87467/commits/b86df2bec4f377afc0ca03482ffad2f0a49a83b8"
},
{
"type": "WEB",
"url": "https://github.com/go-yaml/yaml/commit/53403b58ad1b561927d19068c655246f2db79d48"
},
{
"type": "WEB",
"url": "https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=18496"
},
{
"type": "WEB",
"url": "https://groups.google.com/d/msg/kubernetes-announce/ALL9s73E5ck/4yHe8J-PBAAJ"
},
{
"type": "WEB",
"url": "https://pkg.go.dev/vuln/GO-2020-0036"
},
{
"type": "WEB",
"url": "https://security.netapp.com/advisory/ntap-20200413-0003"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
],
"summary": "Excessive Platform Resource Consumption within a Loop in Kubernetes"
}
No mitigation information available for this CWE.
No CAPEC attack patterns related to this CWE.