UBUNTU-CVE-2026-45063
A vulnerability in the Symfony PHP framework's X509Authenticator component allows an attacker with a trusted certificate containing a crafted emailAddress attribute in the distinguished name to authenticate as another user. This occurs due to an unanchored regular expression matching emailAddress anywhere in the DN, enabling impersonation. The issue affects multiple Symfony versions prior to 5.4.52, 6.4.40, 7.4.12, and 8.0.12. Fixed versions have been released to address this authentication bypass.
AI Analysis
Technical Summary
Symfony's X509Authenticator extracts the user identifier from the $_SERVER['SSL_CLIENT_S_DN'] variable using an unanchored regex that matches emailAddress= anywhere in the distinguished name (DN). An attacker possessing a trusted certificate can include emailAddress=victim inside another Relative Distinguished Name (RDN) value such as CN, causing the authenticator to incorrectly authenticate the attacker as the victim. This vulnerability affects Symfony versions prior to 5.4.52, 6.4.40, 7.4.12, and 8.0.12. The issue is resolved in these fixed versions.
Potential Impact
An attacker with a trusted certificate can exploit this vulnerability to impersonate another user by manipulating the emailAddress attribute in the certificate's distinguished name. This leads to unauthorized authentication as the victim user, potentially allowing access to sensitive resources or actions within applications using the affected Symfony versions.
Mitigation Recommendations
Upgrade affected Symfony versions to 5.4.52, 6.4.40, 7.4.12, or 8.0.12 or later, where the vulnerability is fixed. No other mitigation or temporary workaround is indicated. Patch status is confirmed by the vendor advisory specifying fixed versions.
UBUNTU-CVE-2026-45063
Description
A vulnerability in the Symfony PHP framework's X509Authenticator component allows an attacker with a trusted certificate containing a crafted emailAddress attribute in the distinguished name to authenticate as another user. This occurs due to an unanchored regular expression matching emailAddress anywhere in the DN, enabling impersonation. The issue affects multiple Symfony versions prior to 5.4.52, 6.4.40, 7.4.12, and 8.0.12. Fixed versions have been released to address this authentication bypass.
CVSS v4.0
Affected software
pkg:deb/ubuntu/[email protected]?arch=source&distro=xenialpkg:deb/ubuntu/[email protected]+dfsg-1ubuntu0.1+esm2?arch=source&distro=esm-apps/bionicpkg:deb/ubuntu/[email protected]+dfsg-1ubuntu1+esm2?arch=source&distro=esm-apps/focalpkg:deb/ubuntu/[email protected]+dfsg-1ubuntu8+esm1?arch=source&distro=esm-apps/jammypkg:deb/ubuntu/[email protected]+dfsg-3ubuntu3+esm1?arch=source&distro=esm-apps/noblepkg:deb/ubuntu/[email protected]+dfsg-1?arch=source&distro=questingpkg:deb/ubuntu/[email protected]+dfsg-1ubuntu1?arch=source&distro=resoluteRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Symfony's X509Authenticator extracts the user identifier from the $_SERVER['SSL_CLIENT_S_DN'] variable using an unanchored regex that matches emailAddress= anywhere in the distinguished name (DN). An attacker possessing a trusted certificate can include emailAddress=victim inside another Relative Distinguished Name (RDN) value such as CN, causing the authenticator to incorrectly authenticate the attacker as the victim. This vulnerability affects Symfony versions prior to 5.4.52, 6.4.40, 7.4.12, and 8.0.12. The issue is resolved in these fixed versions.
Potential Impact
An attacker with a trusted certificate can exploit this vulnerability to impersonate another user by manipulating the emailAddress attribute in the certificate's distinguished name. This leads to unauthorized authentication as the victim user, potentially allowing access to sensitive resources or actions within applications using the affected Symfony versions.
Mitigation Recommendations
Upgrade affected Symfony versions to 5.4.52, 6.4.40, 7.4.12, or 8.0.12 or later, where the vulnerability is fixed. No other mitigation or temporary workaround is indicated. Patch status is confirmed by the vendor advisory specifying fixed versions.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- UBUNTU-CVE-2026-45063
- Osv Schema Version
- 1.7.0
- Aliases
- []
- Ecosystems
- ["Ubuntu:16.04:LTS","Ubuntu:Pro:18.04:LTS","Ubuntu:Pro:20.04:LTS","Ubuntu:Pro:22.04:LTS","Ubuntu:Pro:24.04:LTS","Ubuntu:25.10","Ubuntu:26.04:LTS"]
- Database Specific Severity
- null
- Cvss Version
- 4.0
Threat ID: 6a58b4b168715ace43da95d4
Added to database: 07/16/2026, 10:38:41 UTC
Last enriched: 07/16/2026, 12:50:55 UTC
Last updated: 07/16/2026, 12:50:55 UTC
Views: 2
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