CWE-347
AllowedImproper Verification of Cryptographic Signature
Abstraction: Base · Status: Draft
The product does not verify, or incorrectly verifies, the cryptographic signature for data.
1418 vulnerabilities reference this CWE, most recent first.
GHSA-RHPJ-FHRV-WQ93
Vulnerability from github – Published: 2024-12-19 00:37 – Updated: 2024-12-19 00:37A library injection vulnerability exists in Microsoft Outlook 16.83.3 for macOS. A specially crafted library can leverage Outlook's access privileges, leading to a permission bypass. A malicious application could inject a library and start the program to trigger this vulnerability and then make use of the vulnerable application's permissions.
{
"affected": [],
"aliases": [
"CVE-2024-42220"
],
"database_specific": {
"cwe_ids": [
"CWE-347"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-12-18T23:15:08Z",
"severity": "HIGH"
},
"details": "A library injection vulnerability exists in Microsoft Outlook 16.83.3 for macOS. A specially crafted library can leverage Outlook\u0027s access privileges, leading to a permission bypass. A malicious application could inject a library and start the program to trigger this vulnerability and then make use of the vulnerable application\u0027s permissions.",
"id": "GHSA-rhpj-fhrv-wq93",
"modified": "2024-12-19T00:37:35Z",
"published": "2024-12-19T00:37:35Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-42220"
},
{
"type": "WEB",
"url": "https://talosintelligence.com/vulnerability_reports/TALOS-2024-1972"
},
{
"type": "WEB",
"url": "https://www.talosintelligence.com/vulnerability_reports/TALOS-2024-1972"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-RHXJ-GH46-JVW8
Vulnerability from github – Published: 2024-05-14 22:22 – Updated: 2024-11-18 16:26Today we are releasing Grafana 9.2. Alongside with new features and other bug fixes, this release includes a Moderate severity security fix for CVE-2022-31123
We are also releasing security patches for Grafana 9.1.8 and Grafana 8.5.14 to fix these issues.
Release 9.2, latest release, also containing security fix:
Release 9.1.8, only containing security fix:
Release 8.5.14, only containing security fix:
Appropriate patches have been applied to Grafana Cloud and as always, we closely coordinated with all cloud providers licensed to offer Grafana Pro. They have received early notification under embargo and confirmed that their offerings are secure at the time of this announcement. This is applicable to Amazon Managed Grafana and Azure's Grafana as a service offering.
CVE-2022-31123
Summary
On July 4th as a result of an internal security audit we have discovered a bypass in the plugin signature verification by exploiting a versioning flaw.
We believe that this vulnerability is rated at CVSS 6.1 (CVSS:3.1/AV:L/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:L).
Impact
An attacker can convince a server admin to download and successfully run a malicious plugin even though unsigned plugins are not allowed.
Impacted versions
All installations for Grafana versions <=9.x, <=8.x, <=7.x
Solutions and mitigations
To fully address CVE-2022-31123 please upgrade your Grafana instances. Appropriate patches have been applied to Grafana Cloud.
Reporting security issues
If you think you have found a security vulnerability, please send a report to security@grafana.com. This address can be used for all of Grafana Labs' open source and commercial products (including, but not limited to Grafana, Grafana Cloud, Grafana Enterprise, and grafana.com). We can accept only vulnerability reports at this address. We would prefer that you encrypt your message to us by using our PGP key. The key fingerprint is
F988 7BEA 027A 049F AE8E 5CAA D125 8932 BE24 C5CA
The key is available from keyserver.ubuntu.com.
Security announcements
We maintain a security category on our blog, where we will always post a summary, remediation, and mitigation details for any patch containing security fixes.
You can also subscribe to our RSS feed.
{
"affected": [
{
"package": {
"ecosystem": "Go",
"name": "github.com/grafana/grafana"
},
"ranges": [
{
"events": [
{
"introduced": "9.0.0"
},
{
"fixed": "9.1.8"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "Go",
"name": "github.com/grafana/grafana"
},
"ranges": [
{
"events": [
{
"introduced": "7.0.0"
},
{
"fixed": "8.5.14"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2022-31123"
],
"database_specific": {
"cwe_ids": [
"CWE-347"
],
"github_reviewed": true,
"github_reviewed_at": "2024-05-14T22:22:57Z",
"nvd_published_at": "2022-10-13T22:15:00Z",
"severity": "HIGH"
},
"details": "Today we are releasing Grafana 9.2. Alongside with new features and other bug fixes, this release includes a Moderate severity security fix for CVE-2022-31123\n\nWe are also releasing security patches for Grafana 9.1.8 and Grafana 8.5.14 to fix these issues.\n\nRelease 9.2, latest release, also containing security fix:\n\n- [Download Grafana 9.2](https://grafana.com/grafana/download/9.2)\n\nRelease 9.1.8, only containing security fix:\n\n- [Download Grafana 9.1.8](https://grafana.com/grafana/download/9.1.8)\n\nRelease 8.5.14, only containing security fix:\n\n- [Download Grafana 8.5.14](https://grafana.com/grafana/download/8.5.14)\n\nAppropriate patches have been applied to [Grafana Cloud](https://grafana.com/cloud) and as always, we closely coordinated with all cloud providers licensed to offer Grafana Pro. They have received early notification under embargo and confirmed that their offerings are secure at the time of this announcement. This is applicable to Amazon Managed Grafana and Azure\u0027s Grafana as a service offering.\n\n## CVE-2022-31123\n\n### Summary\nOn July 4th as a result of an internal security audit we have discovered a bypass in the plugin signature verification by exploiting a versioning flaw.\n\nWe believe that this vulnerability is rated at CVSS 6.1 (CVSS:3.1/AV:L/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:L). \n\n### Impact\nAn attacker can convince a server admin to download and successfully run a malicious plugin even though [unsigned plugins](https://grafana.com/docs/grafana/latest/administration/plugin-management/#allow-unsigned-plugins) are not allowed.\n\n### Impacted versions\n\nAll installations for Grafana versions \u003c=9.x, \u003c=8.x, \u003c=7.x\n\n### Solutions and mitigations\n\nTo fully address CVE-2022-31123 please upgrade your Grafana instances. \nAppropriate patches have been applied to [Grafana Cloud](https://grafana.com/cloud).\n\n### Reporting security issues\n\nIf you think you have found a security vulnerability, please send a report to security@grafana.com. This address can be used for all of Grafana Labs\u0027 open source and commercial products (including, but not limited to Grafana, Grafana Cloud, Grafana Enterprise, and grafana.com). We can accept only vulnerability reports at this address. We would prefer that you encrypt your message to us by using our PGP key. The key fingerprint is\n\nF988 7BEA 027A 049F AE8E 5CAA D125 8932 BE24 C5CA\n\nThe key is available from keyserver.ubuntu.com.\n\n### Security announcements\n\nWe maintain a [security category](https://community.grafana.com/c/support/security-announcements) on our blog, where we will always post a summary, remediation, and mitigation details for any patch containing security fixes.\n\nYou can also subscribe to our [RSS feed](https://grafana.com/tags/security/index.xml).",
"id": "GHSA-rhxj-gh46-jvw8",
"modified": "2024-11-18T16:26:41Z",
"published": "2024-05-14T22:22:57Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/grafana/grafana/security/advisories/GHSA-rhxj-gh46-jvw8"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-31123"
},
{
"type": "PACKAGE",
"url": "https://github.com/grafana/grafana"
},
{
"type": "WEB",
"url": "https://github.com/grafana/grafana/releases/tag/v9.1.8"
},
{
"type": "WEB",
"url": "https://security.netapp.com/advisory/ntap-20221124-0002"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:L",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "Grafana Plugin signature bypass"
}
GHSA-RJ4R-5Q3X-JCJP
Vulnerability from github – Published: 2022-05-13 01:02 – Updated: 2022-05-13 01:02Insufficient consistency checks in signature handling in the networking stack in Google Chrome prior to 58.0.3029.81 for Mac, Windows, and Linux, and 58.0.3029.83 for Android, allowed a remote attacker to incorrectly accept a badly formed X.509 certificate via a crafted HTML page.
{
"affected": [],
"aliases": [
"CVE-2017-5066"
],
"database_specific": {
"cwe_ids": [
"CWE-347"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2017-10-27T05:29:00Z",
"severity": "MODERATE"
},
"details": "Insufficient consistency checks in signature handling in the networking stack in Google Chrome prior to 58.0.3029.81 for Mac, Windows, and Linux, and 58.0.3029.83 for Android, allowed a remote attacker to incorrectly accept a badly formed X.509 certificate via a crafted HTML page.",
"id": "GHSA-rj4r-5q3x-jcjp",
"modified": "2022-05-13T01:02:41Z",
"published": "2022-05-13T01:02:41Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2017-5066"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2017:1124"
},
{
"type": "WEB",
"url": "https://chromereleases.googleblog.com/2017/04/stable-channel-update-for-desktop.html"
},
{
"type": "WEB",
"url": "https://crbug.com/690821"
},
{
"type": "WEB",
"url": "https://security.gentoo.org/glsa/201705-02"
},
{
"type": "WEB",
"url": "http://www.securityfocus.com/bid/97939"
},
{
"type": "WEB",
"url": "http://www.securitytracker.com/id/1038317"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-RJJJ-VG83-2J3W
Vulnerability from github – Published: 2025-12-12 21:31 – Updated: 2025-12-17 21:30A downgrade issue affecting Intel-based Mac computers was addressed with additional code-signing restrictions. This issue is fixed in macOS Sequoia 15.7.3. An app may be able to access user-sensitive data.
{
"affected": [],
"aliases": [
"CVE-2025-43522"
],
"database_specific": {
"cwe_ids": [
"CWE-347"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-12-12T21:15:57Z",
"severity": "LOW"
},
"details": "A downgrade issue affecting Intel-based Mac computers was addressed with additional code-signing restrictions. This issue is fixed in macOS Sequoia 15.7.3. An app may be able to access user-sensitive data.",
"id": "GHSA-rjjj-vg83-2j3w",
"modified": "2025-12-17T21:30:43Z",
"published": "2025-12-12T21:31:39Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-43522"
},
{
"type": "WEB",
"url": "https://support.apple.com/en-us/125886"
},
{
"type": "WEB",
"url": "https://support.apple.com/en-us/125887"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-RPJ7-HR7H-W6P9
Vulnerability from github – Published: 2026-06-19 20:46 – Updated: 2026-06-19 20:46Impact
When a service is configured to validate SAML tokens using a method other than X.509 certificate signing, the final signature verification is skipped.
Preconditions
The service is configured to authenticate using SAML tokens and an out of band token resolver (commonly the IssuerTokenResolver of IssuedTokenServiceCredential) holds a non-X.509 SecurityToken whose key identifier the attacker can reference in the assertion’s <KeyInfo> - for example a BinarySecretSecurityToken representing the symmetric proof key issued by a WS-Trust symmetric-key holder-of-key STS.
Patches
Fixed in CoreWCF v1.8.1 and v1.9.1
Workarounds
None
{
"affected": [
{
"package": {
"ecosystem": "NuGet",
"name": "CoreWCF.Primitives"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "1.8.1"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "NuGet",
"name": "CoreWCF.Primitives"
},
"ranges": [
{
"events": [
{
"introduced": "1.9.0"
},
{
"fixed": "1.9.1"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-54774"
],
"database_specific": {
"cwe_ids": [
"CWE-345",
"CWE-347"
],
"github_reviewed": true,
"github_reviewed_at": "2026-06-19T20:46:46Z",
"nvd_published_at": null,
"severity": "HIGH"
},
"details": "### Impact\nWhen a service is configured to validate SAML tokens using a method other than X.509 certificate signing, the final signature verification is skipped.\n\n#### Preconditions\nThe service is configured to authenticate using SAML tokens and an out of band token resolver (commonly the IssuerTokenResolver of IssuedTokenServiceCredential) holds a non-X.509 SecurityToken whose key identifier the attacker can reference in the assertion\u2019s `\u003cKeyInfo\u003e` - for example a `BinarySecretSecurityToken` representing the symmetric proof key issued by a WS-Trust symmetric-key holder-of-key STS.\n\n### Patches\nFixed in CoreWCF v1.8.1 and v1.9.1\n\n### Workarounds\nNone",
"id": "GHSA-rpj7-hr7h-w6p9",
"modified": "2026-06-19T20:46:46Z",
"published": "2026-06-19T20:46:46Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/CoreWCF/CoreWCF/security/advisories/GHSA-rpj7-hr7h-w6p9"
},
{
"type": "PACKAGE",
"url": "https://github.com/CoreWCF/CoreWCF"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N",
"type": "CVSS_V3"
}
],
"summary": "CoreWCF: SamlSerializer skips SignatureValue verification when SAML signing token is not an X.509 certificate"
}
GHSA-RQMW-G85W-M87F
Vulnerability from github – Published: 2025-12-11 18:30 – Updated: 2025-12-11 18:30An issue was discovered in Foxit PDF and Editor for Windows and macOS before 13.2 and 2025 before 2025.2. A crafted PDF can use JavaScript to alter annotation content and subsequently clear the file's modification status via JavaScript interfaces. This circumvents digital signature verification by hiding document modifications, allowing an attacker to mislead users about the document's integrity and compromise the trustworthiness of signed PDFs.
{
"affected": [],
"aliases": [
"CVE-2025-55311"
],
"database_specific": {
"cwe_ids": [
"CWE-347"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-12-11T16:16:25Z",
"severity": "MODERATE"
},
"details": "An issue was discovered in Foxit PDF and Editor for Windows and macOS before 13.2 and 2025 before 2025.2. A crafted PDF can use JavaScript to alter annotation content and subsequently clear the file\u0027s modification status via JavaScript interfaces. This circumvents digital signature verification by hiding document modifications, allowing an attacker to mislead users about the document\u0027s integrity and compromise the trustworthiness of signed PDFs.",
"id": "GHSA-rqmw-g85w-m87f",
"modified": "2025-12-11T18:30:44Z",
"published": "2025-12-11T18:30:44Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-55311"
},
{
"type": "WEB",
"url": "https://www.foxit.com/support/security-bulletins.html"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-RQW2-HHRF-7936
Vulnerability from github – Published: 2022-05-24 17:17 – Updated: 2024-09-27 21:21An issue was discovered in OpenStack Keystone before 15.0.1, and 16.0.0. The EC2 API doesn't have a signature TTL check for AWS Signature V4. An attacker can sniff the Authorization header, and then use it to reissue an OpenStack token an unlimited number of times.
{
"affected": [
{
"package": {
"ecosystem": "PyPI",
"name": "keystone"
},
"ranges": [
{
"events": [
{
"introduced": "16.0.0.0rc1"
},
{
"fixed": "16.0.0"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "PyPI",
"name": "keystone"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "15.0.1"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2020-12692"
],
"database_specific": {
"cwe_ids": [
"CWE-311",
"CWE-347"
],
"github_reviewed": true,
"github_reviewed_at": "2023-07-13T17:10:16Z",
"nvd_published_at": "2020-05-07T00:15:00Z",
"severity": "MODERATE"
},
"details": "An issue was discovered in OpenStack Keystone before 15.0.1, and 16.0.0. The EC2 API doesn\u0027t have a signature TTL check for AWS Signature V4. An attacker can sniff the Authorization header, and then use it to reissue an OpenStack token an unlimited number of times.",
"id": "GHSA-rqw2-hhrf-7936",
"modified": "2024-09-27T21:21:47Z",
"published": "2022-05-24T17:17:23Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2020-12692"
},
{
"type": "WEB",
"url": "https://bugs.launchpad.net/keystone/+bug/1872737"
},
{
"type": "PACKAGE",
"url": "https://github.com/openstack/keystone"
},
{
"type": "WEB",
"url": "https://github.com/pypa/advisory-database/tree/main/vulns/keystone/PYSEC-2020-56.yaml"
},
{
"type": "WEB",
"url": "https://opendev.org/openstack/keystone/commit/ab89ea749013e7f2c46260f68504f5687763e019"
},
{
"type": "WEB",
"url": "https://security.openstack.org/ossa/OSSA-2020-003.html"
},
{
"type": "WEB",
"url": "https://usn.ubuntu.com/4480-1"
},
{
"type": "WEB",
"url": "https://www.openwall.com/lists/oss-security/2020/05/06/4"
},
{
"type": "WEB",
"url": "http://www.openwall.com/lists/oss-security/2020/05/07/1"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "OpenStack Keystone does not check signature TTL of the EC2 credential auth method"
}
GHSA-RR32-XPF4-HWJ6
Vulnerability from github – Published: 2024-04-09 18:30 – Updated: 2024-04-09 18:30Improper privilege management in the installer for Zoom Desktop Client for Windows before version 5.17.10 may allow an authenticated user to conduct an escalation of privilege via local access.
{
"affected": [],
"aliases": [
"CVE-2024-24694"
],
"database_specific": {
"cwe_ids": [
"CWE-269",
"CWE-347"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-04-09T18:15:08Z",
"severity": "MODERATE"
},
"details": "Improper privilege management in the installer for Zoom Desktop Client for Windows before version 5.17.10 may allow an authenticated user to conduct an escalation of privilege via local access.",
"id": "GHSA-rr32-xpf4-hwj6",
"modified": "2024-04-09T18:30:28Z",
"published": "2024-04-09T18:30:28Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-24694"
},
{
"type": "WEB",
"url": "https://www.zoom.com/en/trust/security-bulletin/zsb-24011"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:N/I:H/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-RRFW-HG9M-J47H
Vulnerability from github – Published: 2021-05-24 16:59 – Updated: 2021-10-08 21:25Impact
An authentication bypass exists in the goxmldsig this library uses to determine if SAML assertions are genuine. An attacker could craft a SAML response that would appear to be valid but would not have been genuinely issued by the IDP.
Patches
Version 0.4.2 bumps the dependency which should fix the issue.
For more information
Please see the advisory in goxmldsig
Credits
The original vulnerability was discovered by @jupenur. Thanks to @russellhaering for the heads up.
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 0.4.1"
},
"package": {
"ecosystem": "Go",
"name": "github.com/russellhaering/goxmldsig"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "0.4.2"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [],
"database_specific": {
"cwe_ids": [
"CWE-347"
],
"github_reviewed": true,
"github_reviewed_at": "2021-05-21T22:23:03Z",
"nvd_published_at": null,
"severity": "CRITICAL"
},
"details": "### Impact\n\nAn authentication bypass exists in the [goxmldsig](https://github.com/russellhaering/goxmldsig/security/advisories/GHSA-q547-gmf8-8jr7) this library uses to determine if SAML assertions are genuine. An attacker could craft a SAML response that would appear to be valid but would not have been genuinely issued by the IDP.\n\n### Patches\n\nVersion 0.4.2 bumps the dependency which should fix the issue.\n\n### For more information\n\nPlease see [the advisory in goxmldsig](https://github.com/russellhaering/goxmldsig/security/advisories/GHSA-q547-gmf8-8jr7)\n\n## Credits\n\nThe original vulnerability was discovered by @jupenur. Thanks to @russellhaering for the heads up.",
"id": "GHSA-rrfw-hg9m-j47h",
"modified": "2021-10-08T21:25:26Z",
"published": "2021-05-24T16:59:42Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/crewjam/saml/security/advisories/GHSA-rrfw-hg9m-j47h"
},
{
"type": "PACKAGE",
"url": "https://github.com/russellhaering/goxmldsig"
}
],
"schema_version": "1.4.0",
"severity": [],
"summary": "Signature Validation Bypass"
}
GHSA-RRJ9-5Q2J-4GVR
Vulnerability from github – Published: 2026-06-15 17:32 – Updated: 2026-06-15 17:32Description
Symfony\Component\Mailer\Bridge\Mailomat\Webhook\MailomatRequestParser::validateSignature() parses the X-MOM-Webhook-Signature request header as algo=signature and passes the wire-supplied $algo directly to hash_hmac() when verifying the request against the configured webhook secret. The request therefore selects the HMAC primitive used to authenticate it.
PHP's hash_hmac() enforces only that the chosen algorithm is HMAC-compatible. That set still includes primitives with known cryptanalysis (md4, md5, ripemd128, tiger128,3, … — e.g. existential forgery of HMAC-MD4, Contini & Yin, ASIACRYPT 2006). This is the canonical algorithm-confusion shape, analogous to JWT alg=none / alg=HS256 downgrades: any future cryptographic weakness in any HMAC primitive PHP exposes becomes immediately exploitable against a Mailomat webhook receiver, the moment an attacker is in a position to compute a signature for that primitive, without a code change on the Symfony side.
Mailomat's documented webhook security pins SHA-256; the parser did not.
Resolution
MailomatRequestParser::validateSignature() now requires the signature header to be of the form sha256=<hex> and verifies the signature with HMAC-SHA256 keyed by the configured secret using a constant-time comparison. Any other algorithm declared on the wire (including the HMAC primitives PHP would otherwise accept) is rejected.
The patch for this issue is available here for branch 7.4 (and forward-ported to 8.0 and 8.1).
Credits
Symfony would like to thank Omar Alshammari, Essam Alanazi and Alwaleed Alshammari for reporting the issue and Nicolas Grekas for providing the fix.
{
"affected": [
{
"package": {
"ecosystem": "Packagist",
"name": "symfony/mailomat-mailer"
},
"ranges": [
{
"events": [
{
"introduced": "7.2.0"
},
{
"fixed": "7.4.13"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "Packagist",
"name": "symfony/mailomat-mailer"
},
"ranges": [
{
"events": [
{
"introduced": "8.0.0"
},
{
"fixed": "8.0.13"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "Packagist",
"name": "symfony/symfony"
},
"ranges": [
{
"events": [
{
"introduced": "7.2.0"
},
{
"fixed": "7.4.13"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "Packagist",
"name": "symfony/symfony"
},
"ranges": [
{
"events": [
{
"introduced": "8.0.0"
},
{
"fixed": "8.0.13"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-48747"
],
"database_specific": {
"cwe_ids": [
"CWE-347",
"CWE-757"
],
"github_reviewed": true,
"github_reviewed_at": "2026-06-15T17:32:28Z",
"nvd_published_at": null,
"severity": "MODERATE"
},
"details": "### Description\n\n`Symfony\\Component\\Mailer\\Bridge\\Mailomat\\Webhook\\MailomatRequestParser::validateSignature()` parses the `X-MOM-Webhook-Signature` request header as `algo=signature` and passes the wire-supplied `$algo` directly to `hash_hmac()` when verifying the request against the configured webhook secret. The request therefore selects the HMAC primitive used to authenticate it.\n\nPHP\u0027s `hash_hmac()` enforces only that the chosen algorithm is HMAC-compatible. That set still includes primitives with known cryptanalysis (`md4`, `md5`, `ripemd128`, `tiger128,3`, \u2026 \u2014 e.g. existential forgery of HMAC-MD4, Contini \u0026 Yin, ASIACRYPT 2006). This is the canonical algorithm-confusion shape, analogous to JWT `alg=none` / `alg=HS256` downgrades: any future cryptographic weakness in any HMAC primitive PHP exposes becomes immediately exploitable against a Mailomat webhook receiver, the moment an attacker is in a position to compute a signature for that primitive, without a code change on the Symfony side.\n\nMailomat\u0027s [documented webhook security](https://api.mailomat.swiss/docs/#tag/webhook-security) pins SHA-256; the parser did not.\n\n### Resolution\n\n`MailomatRequestParser::validateSignature()` now requires the signature header to be of the form `sha256=\u003chex\u003e` and verifies the signature with HMAC-SHA256 keyed by the configured secret using a constant-time comparison. Any other algorithm declared on the wire (including the HMAC primitives PHP would otherwise accept) is rejected.\n\nThe patch for this issue is available [here](https://github.com/symfony/symfony/commit/bdfe9fe0d94d33dfaca0bc2fe0b00b54767b0c88) for branch 7.4 (and forward-ported to 8.0 and 8.1).\n\n### Credits\n\nSymfony would like to thank Omar Alshammari, Essam Alanazi and Alwaleed Alshammari for reporting the issue and Nicolas Grekas for providing the fix.",
"id": "GHSA-rrj9-5q2j-4gvr",
"modified": "2026-06-15T17:32:28Z",
"published": "2026-06-15T17:32:28Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/symfony/symfony/security/advisories/GHSA-rrj9-5q2j-4gvr"
},
{
"type": "WEB",
"url": "https://github.com/symfony/symfony/commit/bdfe9fe0d94d33dfaca0bc2fe0b00b54767b0c88"
},
{
"type": "WEB",
"url": "https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/mailomat-mailer/CVE-2026-48747.yaml"
},
{
"type": "WEB",
"url": "https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/symfony/CVE-2026-48747.yaml"
},
{
"type": "PACKAGE",
"url": "https://github.com/symfony/symfony"
},
{
"type": "WEB",
"url": "https://symfony.com/cve-2026-48747"
}
],
"schema_version": "1.4.0",
"severity": [],
"summary": "Symfony: Mailomat Mailer Webhook Parser Reads the HMAC Algorithm from the Request: Signature Algorithm Downgrade"
}
No mitigation information available for this CWE.
CAPEC-463: Padding Oracle Crypto Attack
An adversary is able to efficiently decrypt data without knowing the decryption key if a target system leaks data on whether or not a padding error happened while decrypting the ciphertext. A target system that leaks this type of information becomes the padding oracle and an adversary is able to make use of that oracle to efficiently decrypt data without knowing the decryption key by issuing on average 128*b calls to the padding oracle (where b is the number of bytes in the ciphertext block). In addition to performing decryption, an adversary is also able to produce valid ciphertexts (i.e., perform encryption) by using the padding oracle, all without knowing the encryption key.
CAPEC-475: Signature Spoofing by Improper Validation
An adversary exploits a cryptographic weakness in the signature verification algorithm implementation to generate a valid signature without knowing the key.