CVE-2026-91767
Published: September 26, 2026Last modified: September 26, 2026
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.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 6.5 |
| Attack Vector | ADJACENT_NETWORK |
| Attack complexity | LOW |
| Privileges required | NONE |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | HIGH |
| Integrity impact | NONE |
| Availability impact | NONE |
| Vector | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | php81 | Unknown (8.1.19-r0) |
| 25 LTS | php83 | Fixed (8.3.35-r0) | |
| Stream | php83 | Fixed (8.3.35-r0) |