Vulnerability Description
Traefik is an HTTP reverse proxy and load balancer. Prior to v2.11.51, v3.6.22, and v3.7.6, Traefik's BasicAuth, DigestAuth, and ForwardAuth middlewares strip canonical-cased spoofed identity headers before writing Traefik's own value, but do not account for underscore-variant header names, which many backends normalize identically to dashed forms. An attacker able to reach a protected route can inject an underscore-variant header that survives Traefik's stripping and reaches the backend alongside, or on the unauthenticated ForwardAuth authResponseHeaders path instead of, the value Traefik intended to set, spoofing identity or authorization context. This issue is fixed in versions v2.11.51, v3.6.22, and v3.7.6.
CVSS Score
CRITICAL
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Traefik | Traefik | < 2.11.51 |
Related Weaknesses (CWE)
References
- https://github.com/traefik/traefik/commit/108a5264473a2cbc8f12d6d691a3c6553cdf2cPatch
- https://github.com/traefik/traefik/pull/13262Issue Tracking
- https://github.com/traefik/traefik/security/advisories/GHSA-x677-9fxg-v5c5PatchVendor Advisory
FAQ
What is CVE-2026-54763?
CVE-2026-54763 is a vulnerability with a CVSS score of 10.0 (CRITICAL). Traefik is an HTTP reverse proxy and load balancer. Prior to v2.11.51, v3.6.22, and v3.7.6, Traefik's BasicAuth, DigestAuth, and ForwardAuth middlewares strip canonical-cased spoofed identity headers ...
How severe is CVE-2026-54763?
CVE-2026-54763 has been rated CRITICAL with a CVSS base score of 10.0/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-54763?
Check the references section above for vendor advisories and patch information. Affected products include: Traefik Traefik.