CVE-2026-91767

Heap-buffer-overflow in php_openssl_matches_wildcard_name on crafted server cert wildcard CN

State: Published
Severity: 6.5 Medium
Published: Sep 25, 2026
Updated: Sep 28, 2026
Reserved: Sep 15, 2026

Description

php_openssl_matches_wildcard_name() in ext/openssl/xp_ssl.c underflows the length argument passed to memchr() when a TLS server certificate presents a wildcard name whose literal characters are together longer than the hostname being verified. A malicious server presenting such a certificate makes the PHP client read up to SIZE_MAX bytes past the end of a heap allocation. The path is reachable from any default client stream, because verify_peer_name is enabled by default.

Scores

CVSS	Score	Vector	Source
3.1	6.5 Medium	CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N	php

Weaknesses

CWE-122 Heap-based buffer overflow

Affected Products

Product	Versions
PHPPHP Group	8.2.* to before 8.2.34Affected 8.3.* to before 8.3.35Affected 8.4.* to before 8.4.26Affected 8.5.* to before 8.5.11Affected

References

https://github.com/php/php-src/security/advisories/GHSA-xr7j-rvgx-xq5pvendor-advisory

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