MEDIUM 4.3 NVD

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

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.

Remediation

$ sudo apt install --only-upgrade php8.4

References

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

Published: 2026-09-25 · Source: NVD · Feed updated: 2026-09-25

This medium severity vulnerability with a CVSS score of 4.3 was published on 2026-09-25 via NVD. A remediation command is available below.

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