CVE-2026-91769

Name	CVE-2026-91769
Description	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.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
References	DSA-6514-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
php8.2 (PTS)	bookworm	8.2.32-1~deb12u1	vulnerable
	bookworm (security)	8.2.33-1~deb12u1	vulnerable
php8.4 (PTS)	trixie	8.4.24-1~deb13u1	vulnerable
	trixie (security)	8.4.26-1~deb13u1	fixed
	forky, sid	8.4.24-1	vulnerable

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Origin
php8.2	source	(unstable)	(unfixed)
php8.4	source	trixie	8.4.26-1~deb13u1	DSA-6514-1
php8.4	source	(unstable)	(unfixed)

https://github.com/php/php-src/security/advisories/GHSA-vvx9-73fr-5jjx
https://github.com/php/php-src/blob/php-8.4.26/NEWS