Sensiolabs Symfony — CVE-2026-45063 (Critical)

Date Jul 14, 2026

Type Vendor advisory

Signal Critical vendor advisory

Vendor / Product Sensiolabs · Symfony

CVE CVE-2026-45063

Critical vendor advisory CVE-2026-45063

Summary

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.

Why it matters

This CVE carries a CRITICAL severity rating (CVSS 9.1) in Sensiolabs Symfony. Patch or mitigate promptly. EPSS percentile: 26%.

Operator check

Review CVE-2026-45063 in your asset inventory. Apply patches per vendor guidance and verify Symfony is not exposed. CVSS score: 9.1. EPSS probability: 0.3%; percentile: 26%.

Sources

NVD — CVE-2026-45063 Source reference Source reference

PatchBrief uses public sources. It does not scan environments, verify exposure, or replace vendor guidance.

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