CVE-2026-91767

Medium

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.

SeverityMedium

CVSS6.5

Exploit probability—

Product

Php

PublishedSep 25, 2026

First seenSep 25, 2026

Weakness typeCWE-122CWE-122

How to fix

Update

php php8.2.34, 8.3.35, 8.4.26, 8.5.11 or later

Vendor advisories

github.com/php/php-src/security/advisories/GHSA-xr7j-rvgx-xq5p

Affected products

Product	Affected versions	Fixed in
php php	8.2.0 ≤ v < 8.2.34, 8.3.0 ≤ v < 8.3.35, 8.4.0 ≤ v < 8.4.26, 8.5.0 ≤ v < 8.5.11	8.2.34, 8.3.35, 8.4.26, 8.5.11

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