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.

Project Subscriptions

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Advisories
Source ID Title
Debian DSA Debian DSA DSA-6514-1 php8.4 security update
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Sat, 26 Sep 2026 00:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-125
References
Metrics threat_severity

None

threat_severity

Moderate


Fri, 25 Sep 2026 21:00:00 +0000

Type Values Removed Values Added
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.
Title Heap-buffer-overflow in php_openssl_matches_wildcard_name on crafted server cert wildcard CN
Weaknesses CWE-122
References
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: php

Published:

Updated: 2026-09-25T20:53:42.587Z

Reserved: 2026-09-15T00:41:16.041Z

Link: CVE-2026-91767

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-25T21:17:24.793

Modified: 2026-09-25T21:17:24.793

Link: CVE-2026-91767

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-09-25T20:53:42Z

Links: CVE-2026-91767 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-09-25T23:00:15Z

Weaknesses