CVE-2026-91769

PHP's OpenSSL stream peer verification checks the certificate's subjectAltName entries first and, whenever no entry matches, falls back to the Common Name. RFC 6125 requires the CN to be ignored once the certificate presents any service identity, so a certificate carrying a non-matching DNS SAN was still accepted when its CN matched the requested peer_name. A certificate trusted by the client for one name can therefore be used to impersonate another.

CVSS v3 4.3 MEDIUM

4.3^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 1.4

Attack Vector ADJACENT_NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact LOW

Integrity Impact NONE

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/php/php-src/security/advisories/GHSA-vvx9-73fr-5jjx	Vendor Advisory Exploit

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:php:php::::::::
	cpe:2.3:a:php:php::::::::
	cpe:2.3:a:php:php::::::::
	cpe:2.3:a:php:php::::::::

History

23 Oct 2026, 13:20

Type	Values Removed	Values Added
First Time		Php php Php
References	~~() https://github.com/php/php-src/security/advisories/GHSA-vvx9-73fr-5jjx -~~	() https://github.com/php/php-src/security/advisories/GHSA-vvx9-73fr-5jjx - Vendor Advisory, Exploit
CPE		cpe:2.3:a:php:php::::::::

25 Sep 2026, 21:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-09-25 21:17

Updated : 2026-10-23 13:20

NVD link : CVE-2026-91769

Mitre link : CVE-2026-91769

CVE.ORG link : CVE-2026-91769

JSON object : View

Products Affected

php

php

CWE

CWE-297

Improper Validation of Certificate with Host Mismatch

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