CVE-2026-48020

Summary

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.

Affected Software

VendorProductVersion RangeStatus
traefiktraefik>= 3.7.0-ea.1, < 3.7.3affected
traefiktraefik>= 3.0.0-beta1, < 3.6.19affected
traefiktraefik< 2.11.48affected

Weaknesses

  • CWE-288: CWE-288: Authentication Bypass Using an Alternate Path or Channel

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: yes
    • Technical Impact: partial

github.com/traefik/traefik: Traefik: Authentication bypass in StripPrefix middleware allows unauthorized access to protected paths

Additional References

References