CVE-2026-91769NVD

Vulnerability 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 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.

Severity Level

MEDIUM(4.3)

Published Date

Sep 25, 2026

Last Modified

Sep 25, 2026

Exploitation Status

No confirmed exploitation yet

CVE Record Status

Published

EPSS Score (30-Day)

Data Pending

Root Weakness (CWE)

CWE-297: Unknown/Unlisted Weakness ↗

Refer to the official MITRE database for detailed architectural specifications regarding this weakness.

CVSS v3.1 Base Metrics — Score 4.3 (MEDIUM)

Attack VectorAdjacent

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

ConfidentialityLow

IntegrityNone

AvailabilityNone

Affected & Patched Versions

Affected Versions

Not provided by NVD for this CVE.

Patched Versions

Not provided by NVD for this CVE.

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