9.1
CRITICAL CVSS 4.0
CVE-2026-45063
Symfony: Identity Spoofing via Unanchored DN Regex in X509Authenticator
Description

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.

INFO

Published Date :

July 14, 2026, 7:17 p.m.

Last Modified :

July 14, 2026, 8:25 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-45063 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 4.0 CRITICAL [email protected]
Solution
Update Symfony to a patched version to fix vulnerable X509 authentication.
  • Update Symfony to version 5.4.52 or later.
  • Update Symfony to version 6.4.40 or later.
  • Update Symfony to version 7.4.12 or later.
  • Update Symfony to version 8.0.12 or later.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-45063 is associated with the following CWEs:

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-45063 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-45063 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jul. 14, 2026

    Action Type Old Value New Value
    Added SSVC {'id': 'CVE-2026-45063', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-07-14T19:40:45.430489Z'}
  • New CVE Received by [email protected]

    Jul. 14, 2026

    Action Type Old Value New Value
    Added Affected [{'vendor': 'symfony', 'product': 'symfony', 'versions': [{'status': 'affected', 'version': '< 5.4.52'}, {'status': 'affected', 'version': '>= 6.0.0-BETA1, < 6.4.40'}, {'status': 'affected', 'version': '>= 7.0.0-BETA1, < 7.4.12'}, {'status': 'affected', 'version': '>= 8.0.0-BETA1, < 8.0.12'}]}]
    Added Description 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.
    Added CVSS V4.0 AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CWE CWE-290
    Added Reference https://github.com/symfony/symfony/commit/59ef484029601a7af06f5e06c6ed921fdcea5a0d
    Added Reference https://github.com/symfony/symfony/releases/tag/v5.4.52
    Added Reference https://github.com/symfony/symfony/releases/tag/v6.4.40
    Added Reference https://github.com/symfony/symfony/releases/tag/v7.4.12
    Added Reference https://github.com/symfony/symfony/releases/tag/v8.0.12
    Added Reference https://github.com/symfony/symfony/security/advisories/GHSA-ph86-p8f6-f9r2
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.