---
id: CVE-2026-91769
title: >-
  PHP's OpenSSL stream peer verification checks the certificate's subjectAltName
  entries first and, whenever no entry matches, falls back to the Common Name
summary: >-
  PHP's OpenSSL stream peer verification checks the certificate's subjectAltName
  entries first and, whenever no entry matches, falls back to the Common Name.
  RFC 6125 requires the CN to be ignored once the certificate presents any
  service …
severity: medium
cvss: 4.3
cvssVector: 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N'
cwe:
  - CWE-297
  - CWE-295
vendor: PHP Group
product: ext-openssl
affected:
  - ext-openssl >= 8.2.* < 8.2.34
  - ext-openssl >= 8.3.* < 8.3.35
  - ext-openssl >= 8.4.* < 8.4.26
  - ext-openssl >= 8.5.* < 8.5.11
patched:
  - hardened_images
published: '2026-09-25'
updated: '2026-09-29'
sourceUpdated: '2026-09-29T21:27:41.130'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-91769'
references:
  - url: 'https://github.com/php/php-src/security/advisories/GHSA-vvx9-73fr-5jjx'
    label: security@php.net
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-91769.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-91769'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2542493'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-91769'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-91769'
  - url: 'https://access.redhat.com/errata/RHSA-2026:70720'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.00159
epssPercentile: 0.05026
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-28T12:56:47.310384Z'
ingestedAt: '2026-09-25T21:19:40.146Z'
---

## Overview

PHP's OpenSSL stream peer verification checks the certificate's subjectAltName entries first and, whenever no entry matches, falls back to the Common Name. RFC 6125 requires the CN to be ignored once the certificate presents any service identity, so a certificate carrying a non-matching DNS SAN was still accepted when its CN matched the requested peer_name. A certificate trusted by the client for one name can therefore be used to impersonate another.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **RHSA-2026:70720** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-09-23 · [advisory](https://access.redhat.com/errata/RHSA-2026:70720)
- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, … · updated 2026-09-30 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-91769.json)