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[ CVE-2026-89134 · Published 27 Sep 2026 ]

Vulnerability in wolfSSL

CVSS 9.1 EPSS <1%Fix available

[ Why it matters ]Priority signals

  • Critical severity: CVSS 9.1

[ Description ]Official description

A certificate with no dNSName SAN but another SAN type present (e.g. registeredID or iPAddress) bypassed the Subject CN dNSName name-constraint check. The CN-as-DNS fallback was gated on cert->subjectCN != NULL && cert->altNames == NULL && !cert->isCA instead of "no dNSName SAN", so an out-of-scope CN was accepted. This incomplete fix from CVE-2026-6731, leading to the name-constraint check issue, was introduced in wolfSSL version 5.9.2.

[ Fixes ]Fixes and patches

[ References ]References