by Kastro
Paper/Archive/CVE-2026-89134

CVE-2026-89134

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

EPSS 0.2%CVSS 9.1
critical.is priorityof 100
29
CVSS 9.1 (NVD)9.1 / 10 × 3027.3Not in CISA KEV+300.0EPSS percentile 6.7.067 × 201.3No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

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

ProductAffectedFixed inSource
wolfSSL5.9.2–CNA

Scores by source

NVD9.1CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
wolfSSL (CNA)6.3CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
CISA ADPSSVCExploitation: none · Automatable: yes · Technical impact: partial

References

refgithub.com/wolfSSL/wolfssl/pull/10837