---
cve: "CVE-2026-89134"
severity: "MEDIUM"
cvss: 6.3
epss: "0.1%"
vendor: "wolfSSL"
kev: false
exploited: false
published: "2026-09-27 10:16:59"
tags: [cve, security, medium]
source: tsecurity.de CVE-Dossier
exported: "2026-10-02T00:45:50+02:00"
---

# CVE-2026-89134

> 6.3 MEDIUM · 🧪 PoC

## Beschreibung

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.

## CNA-Record (Kanon, cvelistV5)

- CNA: **wolfSSL**
- State: PUBLISHED
- Stand: 2026-09-29 16:37:26
- CNA-CVSS: **6.3** (`CVSS: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-Anreicherung (vulnrichment/ADP)

- CISA-SSVC (Coordinator, v2.0.3):
  - Exploitation: **none**
  - Automatable: **yes**
  - Technical Impact: **partial**

## CVSS-Vektor

```
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Hoch | good |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |

## Referenzen

- <https://github.com/wolfSSL/wolfssl/pull/10837>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-89134) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI WID (CSAF)_