Critical severity9.1NVD Advisory· Published Sep 27, 2026· Updated Oct 2, 2026
CVE-2026-89134
CVE-2026-89134
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.
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Affected products
2Patches
Vulnerability mechanics
References
1News mentions
1- wolfSSL 5.9.4 Fixes 11 TLS Security Flaws and Expands Post-Quantum Cryptography SupportCyber Security News · Sep 29, 2026