---
cve: "CVE-2026-53622"
severity: "HIGH"
cvss: 7.8
epss: "29%"
vendor: "traefik"
kev: false
exploited: false
published: "2026-06-23 20:16:48"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-05T09:38:48+02:00"
---

# CVE-2026-53622

> 7.8 HIGH · 🧪 PoC

## Beschreibung

Traefik is an HTTP reverse proxy and load balancer. Prior to 3.7.3, there is a critical vulnerability in Traefik's HTTP/3 (QUIC) TLS configuration selection that allows unauthenticated clients to bypass router-specific mTLS enforcement. When HTTP/3 is enabled on an entrypoint, the TLS handshake selects the applicable TLS configuration through an exact, case-sensitive lookup on the SNI value, which fails to match wildcard host patterns (e.g., *.example.com) or case variants of the configured hostname. Because the handshake falls back to the default TLS configuration — which may not require client certificates — a client can complete the QUIC handshake without presenting a certificate, while the subsequent HTTP routing layer still dispatches the request to a backend protected by a router-specific mTLS policy. The issue affects deployments where HTTP/3 is enabled, a router uses a wildcard Host rule or case-insensitive hostname matching, a router-specific TLSOptions enforces client certificate authentication, and UDP access to the entrypoint is reachable by an attacker. This vulnerability is fixed in 3.7.3.

## CVSS-Vektor

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

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

## Patch verfügbar (OSV)

- 5ea71f1c3af049067a0b6d5afd97bad1cf1a0071 (Commit)

## Referenzen

- <https://github.com/traefik/traefik/security/advisories/GHSA-9cr8-q42q-g8m7>
- <https://github.com/traefik/traefik/releases/tag/v3.7.3>
- <https://access.redhat.com/security/cve/CVE-2026-53622>
- <https://bugzilla.redhat.com/show_bug.cgi?id=2491924>
- <https://community.traefik.io/t/new-security-update-for-traefik-2-11-2-11-48-3-6-3-6-19-and-3-7-3-7-3/29917>
- <https://github.com/traefik/traefik/compare/v3.6.17...v3.6.18>
- <https://github.com/traefik/traefik/pull/13214>
- <https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-53622.json>
- <https://access.redhat.com/errata/RHSA-2026:62260>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-53622) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_