CVE-2026-91769
TLS Hostname Verification Falls Back to CN After SAN Mismatch
MEDIUM 4.3
At a glance
- Source
- NVD
- EPSS
- EPSS 0.16 % · percentile 5 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- php
- NVD status
- Analyzed
Description
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.
Weaknesses (CWE)
- CWE-297 — Improper Validation of Certificate with Host Mismatch
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | MEDIUM 4.3 | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N | php |
| CVSS 3.1 | MEDIUM 4.3 | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N | NVD · security@php.net (Secondary) |
European references
- ENISA EUVD · EUVD-2026-87346
- GCVE · GCVE-0-2026-91769
CERT-FR advisories
- CERTFR-2026-AVI-1227 — Multiples vulnérabilités dans PHP · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:a:php:php:*:*:*:*:*:*:*:*≥ 8.2.0 < 8.2.34cpe:2.3:a:php:php:*:*:*:*:*:*:*:*≥ 8.3.0 < 8.3.35cpe:2.3:a:php:php:*:*:*:*:*:*:*:*≥ 8.4.0 < 8.4.26cpe:2.3:a:php:php:*:*:*:*:*:*:*:*≥ 8.5.0 < 8.5.11
Affected products
| Product | Versions |
|---|---|
| PHP Group · PHP | affected 8.2.* < 8.2.34 ; affected 8.3.* < 8.3.35 ; affected 8.4.* < 8.4.26 ; affected 8.5.* < 8.5.11 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |