What’s Vulnerable › Vulnerabilities
CVE-2026-89134: Subject CN name-constraint check bypassed when non-DNS SAN present
- Severity: critical (CVSS 9.1 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.2% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-09-27 · updated 2026-10-02
- Weakness: CWE-295
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.
Affected products
- wolfSSL: 5.9.2
References
Get alerted when CVE-2026-89134 or the next vulnerability affects your stack