CVE-2026-91767

medium

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…

Vendor / product: Php — php

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.

CVSS

6.5

6.5 (CVSS v3.1)

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Severity source: NVD CVSS v3.1 (nvd@nist.gov)

Timeline (UTC)

Published: 2026-09-25 21:17

Modified: 2026-10-27 13:14

NVD status: Analyzed

Last synced 1 day ago

Verified against the source API 2026-10-28 11:30 UTC

Exploitation

Not listed in CISA KEV (as of last catalog sync)

Absence from KEV does not mean a CVE is not exploited. Exploitation status: unknown (no authoritative evidence in our sources).

Affected products

php / php ≥8.2.0 <8.2.34, ≥8.3.0 <8.3.35, ≥8.4.0 <8.4.26, ≥8.5.0 <8.5.11

Weakness classification (CWE)

CWE-122

Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.

Mitigation & advisories

Vendor advisory: https://github.com/php/php-src/security/advisories/GHSA-xr7j-rvgx-xq5p

References

https://github.com/php/php-src/security/advisories/GHSA-xr7j-rvgx-xq5p security@php.net

Data sources

NVD CVE API 2.0 — fetched 2026-10-28 11:30 UTC · record ↗

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CVE-2026-91767

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Weakness classification (CWE)

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