---
cve: "CVE-2026-5501"
severity: "HIGH"
cvss: 8.6
epss: "0.2%"
vendor: "wolfSSL"
kev: false
exploited: false
published: "2026-04-10 04:17:17"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-21T08:11:39+02:00"
---

# CVE-2026-5501

> 8.6 HIGH · 🧪 PoC

## Beschreibung

wolfSSL_X509_verify_cert in the OpenSSL compatibility layer accepts a certificate chain in which the leaf's signature is not checked, if the attacker supplies an untrusted intermediate with Basic Constraints `CA:FALSE` that is legitimately signed by a trusted root. An attacker who obtains any leaf certificate from a trusted CA (e.g. a free DV cert from Let's Encrypt) can forge a certificate for any subject name with any public key and arbitrary signature bytes, and the function returns `WOLFSSL_SUCCESS` / `X509_V_OK`. The native wolfSSL TLS handshake path (`ProcessPeerCerts`) is not susceptible and the issue is limited to applications using the OpenSSL compatibility API directly, which would include integrations of wolfSSL into nginx and haproxy.

## CVSS-Vektor

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

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

## Referenzen

- <https://github.com/wolfSSL/wolfssl/pull/10102>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-5501) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_