CVE-2026-91767 — Heap-buffer-overflow in php_openssl_matches_wildcard_name on crafted server cert wildcard CN
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 litera…
Published: 2026-09-25 · CVSS: 6.5 · CVSS 3.1
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7