Vulnerability Details CVE-2026-89134
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.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.002
EPSS Ranking 4.2%
CVSS Severity
CVSS v3 Score 9.1