Vulnerability · Published Sep 25, 2026 · Assigned by php
CVE-2026-91767Heap-buffer-overflow in php_openssl_matches_wildcard_name on crafted server cert wildcard CN
Medium 6.5
In plain English
A medium-severity heap buffer overflow in PHP from PHP Group. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 1% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)6.5Medium
Exploit odds (30 days)0.1%top 98.8% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:8 | apcu-panel | 5.1.18-1.module_el8.6.0+2750+78feabcb | ALSA-2026:87080 |
| AlmaLinux:8 | libzip | 1.6.1-1.module_el8.6.0+3239+bedf0508 | ALSA-2026:87080 |
| AlmaLinux:8 | libzip | 1.6.1-1.module_el8.6.0+2750+78feabcb | ALSA-2026:87080 |
| AlmaLinux:8 | libzip | 1.6.1-1.module_el8.10.0+3935+28808425 | ALSA-2026:87080 |
| AlmaLinux:8 | libzip-devel | 1.6.1-1.module_el8.6.0+2750+78feabcb | ALSA-2026:87080 |
| AlmaLinux:8 | libzip-devel | 1.6.1-1.module_el8.10.0+3935+28808425 | ALSA-2026:87080 |
| AlmaLinux:8 | libzip-devel | 1.6.1-1.module_el8.6.0+3239+bedf0508 | ALSA-2026:87080 |
| AlmaLinux:8 | libzip-tools | 1.6.1-1.module_el8.10.0+3935+28808425 | ALSA-2026:87080 |
| AlmaLinux:8 | libzip-tools | 1.6.1-1.module_el8.6.0+3239+bedf0508 | ALSA-2026:87080 |
| AlmaLinux:8 | php | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-bcmath | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-cli | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-common | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-dba | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-dbg | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-devel | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-embedded | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-enchant | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-ffi | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-fpm | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-gd | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-gmp | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-intl | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-json | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-ldap | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-mbstring | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-mysqlnd | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-odbc | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-opcache | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-pdo | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-pear | 1:1.10.13-1.module_el8.10.0+3935+28808425 | ALSA-2026:87080 |
| AlmaLinux:8 | php-pecl-apcu | 5.1.18-1.module_el8.10.0+3935+28808425 | ALSA-2026:87080 |
| AlmaLinux:8 | php-pecl-apcu | 5.1.18-1.module_el8.6.0+2750+78feabcb | ALSA-2026:87080 |
| AlmaLinux:8 | php-pecl-apcu-devel | 5.1.18-1.module_el8.6.0+2750+78feabcb | ALSA-2026:87080 |
| AlmaLinux:8 | php-pecl-apcu-devel | 5.1.18-1.module_el8.10.0+3935+28808425 | ALSA-2026:87080 |
| AlmaLinux:8 | php-pecl-rrd | 2.0.1-1.module_el8.6.0+2750+78feabcb | ALSA-2026:87080 |
| AlmaLinux:8 | php-pecl-rrd | 2.0.1-1.module_el8.6.0+3239+bedf0508 | ALSA-2026:87080 |
| AlmaLinux:8 | php-pecl-rrd | 2.0.1-1.module_el8.10.0+3935+28808425 | ALSA-2026:87080 |
| AlmaLinux:8 | php-pecl-xdebug | 2.9.5-1.module_el8.6.0+3239+bedf0508 | ALSA-2026:87080 |
| AlmaLinux:8 | php-pecl-xdebug | 2.9.5-1.module_el8.6.0+2750+78feabcb | ALSA-2026:87080 |
| AlmaLinux:8 | php-pecl-zip | 1.18.2-1.module_el8.6.0+2750+78feabcb | ALSA-2026:87080 |
| AlmaLinux:8 | php-pecl-zip | 1.18.2-1.module_el8.10.0+3935+28808425 | ALSA-2026:87080 |
| AlmaLinux:8 | php-pecl-zip | 1.18.2-1.module_el8.6.0+3239+bedf0508 | ALSA-2026:87080 |
| AlmaLinux:8 | php-pgsql | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-process | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-snmp | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-soap | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-xml | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-xmlrpc | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| Alpine:v3.22 | php82 | 8.2.35-r0 | ALPINE-CVE-2026-91767 |
| Alpine:v3.22 | php83 | 8.3.36-r0 | ALPINE-CVE-2026-91767 |
| Alpine:v3.23 | php83 | 8.3.36-r0 | ALPINE-CVE-2026-91767 |
| Alpine:v3.24 | php83 | 8.3.35-r0 | ALPINE-CVE-2026-91767 |
| Alpine:v3.22 | php84 | 8.4.27-r0 | ALPINE-CVE-2026-91767 |
| Alpine:v3.23 | php84 | 8.4.27-r0 | ALPINE-CVE-2026-91767 |
| Alpine:v3.24 | php84 | 8.4.26-r0 | ALPINE-CVE-2026-91767 |
| Alpine:v3.23 | php85 | 8.5.12-r0 | ALPINE-CVE-2026-91767 |
| Alpine:v3.24 | php85 | 8.5.11-r0 | ALPINE-CVE-2026-91767 |
| Debian:12 | php8.2 | 8.2.34-1~deb12u1 | DEBIAN-CVE-2026-91767 |
| Debian:13 | php8.4 | 8.4.26-1~deb13u1 | DEBIAN-CVE-2026-91767 |
| Debian:14 | php8.4 | 8.4.26-1 | DEBIAN-CVE-2026-91767 |
| Rocky Linux:8 | libzip | 0:1.6.1-1.module+el8.10.0+1604+6558efc7 | RLSA-2026:87080 |
| Rocky Linux:8 | libzip | 0:1.6.1-1.module+el8.10.0+1912+72767185 | RLSA-2026:87080 |
| Rocky Linux:8 | php | 0:7.4.33-8.module+el8.10.0+40393+c071e357 | RLSA-2026:87080 |
| Rocky Linux:8 | php-pear | 1:1.10.13-1.module+el8.10.0+1605+02e07af7 | RLSA-2026:87080 |
| Rocky Linux:8 | php-pear | 1:1.10.13-1.module+el8.10.0+1912+72767185 | RLSA-2026:87080 |
| Rocky Linux:8 | php-pear | 1:1.10.13-1.module+el8.10.0+1604+6558efc7 | RLSA-2026:87080 |
| Rocky Linux:8 | php-pecl-apcu | 0:5.1.18-1.module+el8.10.0+1604+6558efc7 | RLSA-2026:87080 |
| Rocky Linux:8 | php-pecl-apcu | 0:5.1.18-1.module+el8.10.0+1912+72767185 | RLSA-2026:87080 |
| Rocky Linux:8 | php-pecl-rrd | 0:2.0.1-1.module+el8.10.0+1604+6558efc7 | RLSA-2026:87080 |
| Rocky Linux:8 | php-pecl-rrd | 0:2.0.1-1.module+el8.4.0+414+2e7afcdd | RLSA-2026:87080 |
| Rocky Linux:8 | php-pecl-rrd | 0:2.0.1-1.module+el8.10.0+1912+72767185 | RLSA-2026:87080 |
| Rocky Linux:8 | php-pecl-xdebug | 0:2.9.5-1.module+el8.10.0+1912+72767185 | RLSA-2026:87080 |
| Rocky Linux:8 | php-pecl-xdebug | 0:2.9.5-1.module+el8.10.0+1604+6558efc7 | RLSA-2026:87080 |
| Rocky Linux:8 | php-pecl-zip | 0:1.18.2-1.module+el8.10.0+1604+6558efc7 | RLSA-2026:87080 |
| Rocky Linux:8 | php-pecl-zip | 0:1.18.2-1.module+el8.10.0+1912+72767185 | RLSA-2026:87080 |
| Ubuntu:22.04:LTS | php8.1 | 8.1.2-1ubuntu2.27 | USN-8936-1 |
| Ubuntu:22.04:LTS | php8.1 | 8.1.2-1ubuntu2.27 | UBUNTU-CVE-2026-91767 |
| Ubuntu:24.04:LTS | php8.3 | 8.3.6-0ubuntu0.24.04.12 | UBUNTU-CVE-2026-91767 |
| Ubuntu:24.04:LTS | php8.3 | 8.3.6-0ubuntu0.24.04.12 | USN-8936-1 |
| Ubuntu:26.04:LTS | php8.5 | 8.5.4-0ubuntu1.4 | UBUNTU-CVE-2026-91767 |
| Ubuntu:26.04:LTS | php8.5 | 8.5.4-0ubuntu1.4 | USN-8936-1 |
| Ubuntu:26.10 | php8.5 | 8.5.9-0ubuntu2 | UBUNTU-CVE-2026-91767 |
| Ubuntu:26.10 | php8.5 | 8.5.9-0ubuntu2 | USN-8936-1 |
Affected products (as reported)
Weakness: CWE-122 · Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N