Critical severity · published Jul 14, 2026
CVE-2026-45063
Symfony: Identity Spoofing via Unanchored DN Regex in X509Authenticator
9.1
CVSS
0.4%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 30% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
SY
symfony · symfony
< 5.4.52; >= 6.0.0-BETA1, < 6.4.40; >= 7.0.0-BETA1, < 7.4.12; >= 8.0.0-BETA1, < 8.0.12 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-45063
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-45063
Patch
https://github.com/symfony/symfony/commit/59ef484029601a7af06f5e06c6ed921fdcea5a0d
Product
https://github.com/symfony/symfony/releases/tag/v5.4.52
Product
https://github.com/symfony/symfony/releases/tag/v6.4.40
Product
https://github.com/symfony/symfony/releases/tag/v7.4.12
Product
https://github.com/symfony/symfony/releases/tag/v8.0.12
Patch
https://github.com/symfony/symfony/security/advisories/GHSA-ph86-p8f6-f9r2
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