VYPR
Critical severity10.0OSV Advisory· Published Jul 6, 2026· Updated Jul 8, 2026

CVE-2026-54763

CVE-2026-54763

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.

Affected packages

Versions sourced from the GitHub Security Advisory.

PackageAffected versionsPatched versions
github.com/traefik/traefik/v2Go
< 2.11.512.11.51
github.com/traefik/traefik/v3Go
< 3.6.223.6.22
github.com/traefik/traefik/v3Go
>= 3.7.0, < 3.7.63.7.6

Affected products

5

Patches

Vulnerability mechanics

References

8

News mentions

0

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