All vulnerabilities
CVE-2026-89134

wolfSSL: Subject CN name-constraint check bypassed when non-DNS SAN present

wolfSSL wolfSSL
Open in ThreatlineRecord JSON
CVSS
6.3Medium
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.16%Chance of exploitation activity in the next 30 days, higher than 4% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed inNone listedNo source names a fixed version yet
Published27 Sep 2026Updated 29 Sep 2026CVE List

What fixes it

No source in this snapshot names a fixed version.

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.

Text from CVE List

Affected versions 1

  • wolfSSLaffected: 5.9.2CVE List

References 1