Traefik StripPrefix Route-Level Auth Bypass via Path Normalization_CVE-2026-48020

7.8 / 10

HIGH

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

Description

Traefik is an HTTP reverse proxy and load balancer. Prior to 2.11.48, 3.6.19, and 3.7.3, there is a high severity vulnerability in Traefik's StripPrefix middleware that allows an unauthenticated attacker to bypass route-level authentication and authorization. When a public router matches on a PathPrefix rule and applies the StripPrefix middleware, a request path containing .. or its percent-encoded form %2e%2e can match the public route at routing time and then, after the prefix is stripped and the path is normalized, resolve to a path served by a separate, authenticated router. As a result, an attacker can reach protected backend paths — such as admin or internal configuration endpoints — without satisfying the authentication middleware attached to the protected router. This vulnerability is fixed in 2.11.48, 3.6.19, and 3.7.3.

Basic Information

ID CVE-2026-48020

Source GitHub_M

Published Jun 23, 2026 at 19:10

Affected Product

Vendor traefik

Product traefik

Version >= 3.7.0-ea.1, < 3.7.3

Affected Versions traefik traefik >= 3.7.0-ea.1, < 3.7.3
traefik traefik >= 3.0.0-beta1, < 3.6.19
traefik traefik < 2.11.48

CWE Classification

CWE-288

References

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    "published": "2026-06-23T19:10:31.557Z",
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