CVE-2026-91767

medium
Assigned by CNA: php
Published 2026-09-25 · Modified 2026-09-25
CVSS v3
6.5
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CVSS v4 NEW
—
not yet in upstream
VIR risk
6.5

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.

Predictions

Exploit likelihood
65%
Patch ETA
—

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

No mitigations published for this CVE yet.

The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.

Propose a mitigation on Community Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here with source_tier=community-verified.

OS impact

debian Debian Affected 4 releases
VersionStatusFixed in
trixie Affected —
sid Affected —
forky Affected —
bookworm Affected —
alpine Alpine Fixed 1 release
VersionStatusFixed in
v3.24 Fixed 8.3.35-r0

References

CWEs

CWE-122

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.