USN-8893-1 (UBUNTU-CVE-2026-19773)
Vulnerability from osv_ubuntu – Published: 2026-10-07 10:05 – Updated: 2026-10-07 10:05 – Source website
VLAI
Summary
libwebsockets vulnerabilities
Details
It was discovered that libwebsockets did not properly validate user-supplied data when parsing HTTP/2 HPACK path headers, which could result in a write past the end of an allocated buffer. An attacker could possibly use this issue to execute arbitrary code. (CVE-2026-19773)
It was discovered that libwebsockets did not properly handle CBOR recording in the LECP parser, which could result in a write past the end of an allocated buffer. An attacker could possibly use this issue to cause a crash or execute arbitrary code. (CVE-2026-78161)
References
| URL | Type | |
|---|---|---|
{
"affected": [
{
"database_specific": {
"cves_map": {
"cves": [
{
"id": "CVE-2026-19773",
"severity": [
{
"score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
}
],
"ecosystem": "Ubuntu:Pro:16.04:LTS"
}
},
"ecosystem_specific": {
"availability": "Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro",
"binaries": [
{
"binary_name": "libwebsockets-test-server",
"binary_version": "1.7.1-1ubuntu0.1~esm1"
},
{
"binary_name": "libwebsockets-test-server-common",
"binary_version": "1.7.1-1ubuntu0.1~esm1"
},
{
"binary_name": "libwebsockets7",
"binary_version": "1.7.1-1ubuntu0.1~esm1"
}
]
},
"package": {
"ecosystem": "Ubuntu:Pro:16.04:LTS",
"name": "libwebsockets",
"purl": "pkg:deb/ubuntu/libwebsockets@1.7.1-1ubuntu0.1~esm1?arch=source\u0026distro=esm-apps-legacy/xenial"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "1.7.1-1ubuntu0.1~esm1"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"1.2.2-1",
"1.6.0-3",
"1.6.0-4",
"1.6.0-5",
"1.6.1-1",
"1.7.0-1ubuntu1",
"1.7.0-2",
"1.7.1-1"
]
},
{
"database_specific": {
"cves_map": {
"cves": [
{
"id": "CVE-2026-19773",
"severity": [
{
"score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
}
],
"ecosystem": "Ubuntu:Pro:18.04:LTS"
}
},
"ecosystem_specific": {
"availability": "Available with Ubuntu Pro: https://ubuntu.com/pro",
"binaries": [
{
"binary_name": "libwebsockets-test-server",
"binary_version": "2.0.3-3ubuntu0.1~esm1"
},
{
"binary_name": "libwebsockets-test-server-common",
"binary_version": "2.0.3-3ubuntu0.1~esm1"
},
{
"binary_name": "libwebsockets8",
"binary_version": "2.0.3-3ubuntu0.1~esm1"
}
]
},
"package": {
"ecosystem": "Ubuntu:Pro:18.04:LTS",
"name": "libwebsockets",
"purl": "pkg:deb/ubuntu/libwebsockets@2.0.3-3ubuntu0.1~esm1?arch=source\u0026distro=esm-apps/bionic"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "2.0.3-3ubuntu0.1~esm1"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"2.0.3-3",
"2.0.3-3build1"
]
},
{
"database_specific": {
"cves_map": {
"cves": [
{
"id": "CVE-2026-19773",
"severity": [
{
"score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
}
],
"ecosystem": "Ubuntu:Pro:20.04:LTS"
}
},
"ecosystem_specific": {
"availability": "Available with Ubuntu Pro: https://ubuntu.com/pro",
"binaries": [
{
"binary_name": "libwebsockets-test-server",
"binary_version": "3.2.1-3ubuntu0.1~esm3"
},
{
"binary_name": "libwebsockets-test-server-common",
"binary_version": "3.2.1-3ubuntu0.1~esm3"
},
{
"binary_name": "libwebsockets15",
"binary_version": "3.2.1-3ubuntu0.1~esm3"
}
]
},
"package": {
"ecosystem": "Ubuntu:Pro:20.04:LTS",
"name": "libwebsockets",
"purl": "pkg:deb/ubuntu/libwebsockets@3.2.1-3ubuntu0.1~esm3?arch=source\u0026distro=esm-apps/focal"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "3.2.1-3ubuntu0.1~esm3"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"2.0.3-3build1",
"3.2.1-3",
"3.2.1-3ubuntu0.1~esm1",
"3.2.1-3ubuntu0.1~esm2"
]
},
{
"database_specific": {
"cves_map": {
"cves": [
{
"id": "CVE-2026-19773",
"severity": [
{
"score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
}
],
"ecosystem": "Ubuntu:Pro:22.04:LTS"
}
},
"ecosystem_specific": {
"availability": "Available with Ubuntu Pro: https://ubuntu.com/pro",
"binaries": [
{
"binary_name": "libwebsockets-test-server",
"binary_version": "4.0.20-2ubuntu1.1+esm2"
},
{
"binary_name": "libwebsockets-test-server-common",
"binary_version": "4.0.20-2ubuntu1.1+esm2"
},
{
"binary_name": "libwebsockets16",
"binary_version": "4.0.20-2ubuntu1.1+esm2"
}
]
},
"package": {
"ecosystem": "Ubuntu:Pro:22.04:LTS",
"name": "libwebsockets",
"purl": "pkg:deb/ubuntu/libwebsockets@4.0.20-2ubuntu1.1+esm2?arch=source\u0026distro=esm-apps/jammy"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "4.0.20-2ubuntu1.1+esm2"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"4.0.20-2",
"4.0.20-2ubuntu1",
"4.0.20-2ubuntu1.1",
"4.0.20-2ubuntu1.1+esm1"
]
},
{
"database_specific": {
"cves_map": {
"cves": [
{
"id": "CVE-2026-19773",
"severity": [
{
"score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
}
],
"ecosystem": "Ubuntu:Pro:24.04:LTS"
}
},
"ecosystem_specific": {
"availability": "Available with Ubuntu Pro: https://ubuntu.com/pro",
"binaries": [
{
"binary_name": "libwebsockets-evlib-ev",
"binary_version": "4.3.3-1.1ubuntu0.1~esm3"
},
{
"binary_name": "libwebsockets-evlib-glib",
"binary_version": "4.3.3-1.1ubuntu0.1~esm3"
},
{
"binary_name": "libwebsockets-evlib-uv",
"binary_version": "4.3.3-1.1ubuntu0.1~esm3"
},
{
"binary_name": "libwebsockets-test-server",
"binary_version": "4.3.3-1.1ubuntu0.1~esm3"
},
{
"binary_name": "libwebsockets-test-server-common",
"binary_version": "4.3.3-1.1ubuntu0.1~esm3"
},
{
"binary_name": "libwebsockets19t64",
"binary_version": "4.3.3-1.1ubuntu0.1~esm3"
}
]
},
"package": {
"ecosystem": "Ubuntu:Pro:24.04:LTS",
"name": "libwebsockets",
"purl": "pkg:deb/ubuntu/libwebsockets@4.3.3-1.1ubuntu0.1~esm3?arch=source\u0026distro=esm-apps/noble"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "4.3.3-1.1ubuntu0.1~esm3"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"4.3.2-4",
"4.3.3-1",
"4.3.3-1.1build1",
"4.3.3-1.1build2",
"4.3.3-1.1build3",
"4.3.3-1.1ubuntu0.1~esm1",
"4.3.3-1.1ubuntu0.1~esm2"
]
},
{
"database_specific": {
"cves_map": {
"cves": [
{
"id": "CVE-2026-19773",
"severity": [
{
"score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
]
}
],
"ecosystem": "Ubuntu:Pro:26.04:LTS"
}
},
"ecosystem_specific": {
"availability": "Available with Ubuntu Pro: https://ubuntu.com/pro",
"binaries": [
{
"binary_name": "libwebsockets-evlib-ev",
"binary_version": "4.3.5-3ubuntu1.2+esm1"
},
{
"binary_name": "libwebsockets-evlib-glib",
"binary_version": "4.3.5-3ubuntu1.2+esm1"
},
{
"binary_name": "libwebsockets-evlib-uv",
"binary_version": "4.3.5-3ubuntu1.2+esm1"
},
{
"binary_name": "libwebsockets-test-server",
"binary_version": "4.3.5-3ubuntu1.2+esm1"
},
{
"binary_name": "libwebsockets-test-server-common",
"binary_version": "4.3.5-3ubuntu1.2+esm1"
},
{
"binary_name": "libwebsockets19t64",
"binary_version": "4.3.5-3ubuntu1.2+esm1"
}
]
},
"package": {
"ecosystem": "Ubuntu:Pro:26.04:LTS",
"name": "libwebsockets",
"purl": "pkg:deb/ubuntu/libwebsockets@4.3.5-3ubuntu1.2+esm1?arch=source\u0026distro=esm-apps/resolute"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "4.3.5-3ubuntu1.2+esm1"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"4.3.5-1",
"4.3.5-3",
"4.3.5-3ubuntu1",
"4.3.5-3ubuntu1.1"
]
}
],
"aliases": [],
"details": "It was discovered that libwebsockets did not properly validate\nuser-supplied data when parsing HTTP/2 HPACK path headers, which could\nresult in a write past the end of an allocated buffer. An attacker could\npossibly use this issue to execute arbitrary code. (CVE-2026-19773)\n\nIt was discovered that libwebsockets did not properly handle CBOR\nrecording in the LECP parser, which could result in a write past the end\nof an allocated buffer. An attacker could possibly use this issue to\ncause a crash or execute arbitrary code. (CVE-2026-78161)",
"id": "USN-8893-1",
"modified": "2026-10-07T10:05:38Z",
"published": "2026-10-07T10:05:38Z",
"references": [
{
"type": "ADVISORY",
"url": "https://ubuntu.com/security/notices/USN-8893-1"
},
{
"type": "REPORT",
"url": "https://ubuntu.com/security/CVE-2026-19773"
}
],
"related": [],
"schema_version": "1.7.0",
"summary": "libwebsockets vulnerabilities",
"upstream": [
"UBUNTU-CVE-2026-19773"
]
}
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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
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- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
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