---
cve: "CVE-2026-88008"
severity: "HIGH"
cvss: 7.0
epss: "34%"
vendor: "traefik"
kev: false
exploited: false
published: "2026-09-10 15:17:56"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-19T21:05:37+02:00"
---

# CVE-2026-88008

> 7.0 HIGH · 🧪 PoC

## Beschreibung

Traefik is an open source HTTP reverse proxy and load balancer. From 2.11.26 until 2.11.57 and 3.7.13, Traefik forwards a client-supplied Connection header requesting Upgrade, the Upgrade: h2c token, and HTTP2-Settings to a shared backend. If the backend accepts h2c and returns 101 Switching Protocols, Traefik enters a raw tunnel and no longer applies routers, BasicAuth, ForwardAuth, IPAllowList, RateLimit, access logging, metrics, or tracing to later HTTP/2 requests, allowing an unauthenticated request through an unprotected route to reach protected paths on the same backend. This issue is fixed in 2.11.57 and 3.7.13.

## CVSS-Vektor

```
CVSS:4.0/AV:N/AC:L/AT:P/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)

- 839eb7f48a16849f22762b7e3bdfc58253146cd7 (Commit)
- fc92cc118a0557a029c7019d5ee06665127b0f13 (Commit)

## Referenzen

- <https://github.com/traefik/traefik/security/advisories/GHSA-w4v4-9rw7-5326>
- <https://github.com/traefik/traefik/pull/13797>
- <https://github.com/traefik/traefik/commit/a277e94664ffc1ce9543df552d3bbf48d4d3b8b3>
- <https://github.com/traefik/traefik/releases/tag/v2.11.57>
- <https://github.com/traefik/traefik/releases/tag/v3.7.13>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-88008) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_