Subject CN name-constraint check bypassed when non-DNS SAN present (CVE-2026-89134) | HOL Guard CVE

Medium · CVSS 6.3CVE-2026-89134

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

Answer in brief

CVE-2026-89134 records a Medium severity (CVSS 6.3) vulnerability in Subject CN name-constraint check bypassed when non-DNS SAN present. The current sources do not mark it as known exploited. The current feed maps wolfSSL/wolfSSL (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 27, 2026Updated Sep 27, 2026Source checked Sep 27, 2026First seen by HOL Sep 27, 2026Material review Sep 27, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 6.3
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

CVSS is 6.3. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps wolfSSL/wolfSSL (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
wolfSSL/wolfSSLgeneric	5.9.2	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for wolfSSL/wolfSSL.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Sep 27, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 27, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 27, 2026

Sources and claim methodology

GitHub security advisorygithub.com

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.