CVE-2026-45063: Sensiolabs Symfony

Critical severity, CVSS 9.1. EPSS: 0.4% chance of exploitation in the next 30 days.

Symfony is a PHP framework for web and console applications and a set of reusable PHP components. Prior to 5.4.52, 6.4.40, 7.4.12, and 8.0.12, X509Authenticator extracts the user identifier from $_SERVER['SSL_CLIENT_S_DN'] with an unanchored regex that matches emailAddress= anywhere in the distinguished name, allowing an attacker with a trusted certificate containing emailAddress=victim inside another RDN value such as CN to authenticate as the victim. This issue is fixed in versions 5.4.52, 6.4.40, 7.4.12, and 8.0.12.

Affected products

• Sensiolabs Symfony: before 5.4.52 (fixed in 5.4.52); from 6.0.0, before 6.4.40 (fixed in 6.4.40); from 7.0.0, before 7.4.12 (fixed in 7.4.12); from 8.0.0, before 8.0.12 (fixed in 8.0.12)

Published 2026-07-14. Last modified 2026-07-15.