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Vulnerability · Published Sep 10, 2026 · Assigned by GitHub_M

CVE-2026-88009Traefik: Rootless HTTP/1 request-target routes as "/" but is forwarded verbatim, bypassing path-scoped routing, middleware guards and access logging

High 8.8

In plain English

A high-severity security flaw in traefik from traefik. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 39% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code. Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)8.8High
Exploit odds (30 days)0.4%top 61.3% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack tooling1Public PoC

Official description

Traefik is an open source HTTP reverse proxy and load balancer. Prior to 2.11.57, and 3.7.13, Traefik accepts a rootless HTTP/1 request target that Go stores in URL.Opaque while leaving URL.Path empty. The rewriteRequestBuilder path evaluates routing, path sanitization, forwardAuth, encodedCharacters, and access logging against a path normalized to / but forwards URL.Opaque verbatim to the backend, allowing cross-vhost routing bypass, path-scoped authorization bypass, and access-log evasion when the backend interprets the opaque target as a path. This issue is fixed in 2.11.57 and 3.7.13.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Gogithub.com/traefik/traefikno fix listedGO-2026-6465
Gogithub.com/traefik/traefik/v22.11.57GHSA-f52w-8j3h-j724
Gogithub.com/traefik/traefik/v22.11.57GO-2026-6465
Gogithub.com/traefik/traefik/v33.7.13GHSA-f52w-8j3h-j724
Gogithub.com/traefik/traefik/v33.7.13GO-2026-6465

Affected products (as reported)

VendorProductVersions
traefik traefik < 2.11.57>= 3.0.0, < 3.7.13

Weakness: CWE-444, CWE-1286 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N

References