CVE-2026-54764
Traefik: ForwardAuth middleware leaks X-Forwarded-Port spoofing via untrusted X-Forwarded-Proto when trustForwardHeader=false
Impact
Traefik is an HTTP reverse proxy and load balancer. Prior to v2.11.51, v3.6.22, and v3.7.6, Traefik's ForwardAuth middleware, even when configured with trustForwardHeader: false, derives the X-Forwarded-Port header sent to the authentication service from the original incoming request instead of the sanitized forwarded request. As a result, an unauthenticated remote attacker can inject an X-Forwarded-Proto: https header over a plain HTTP connection and cause Traefik to forward X-Forwarded-Port: 443 to the authentication service, bypassing port-based authorization checks. This issue is fixed in versions v2.11.51, v3.6.22, and v3.7.6.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| go | github.com/traefik/traefik/v2 | <= 2.11.50 | 2.11.51 |
| go | github.com/traefik/traefik/v3 | <= 3.6.21 | 3.6.22 |
| go | github.com/traefik/traefik | <= 1.7.34 | none recorded |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Traefik | Traefik | before 2.11.51 from 3.0.0 before 3.6.22 from 3.7.0 before 3.7.6 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-3q9r-p662-5j8m
- https://github.com/traefik/traefik/security/advisories/GHSA-3q9r-p662-5j8m
- https://nvd.nist.gov/vuln/detail/CVE-2026-54764
- https://github.com/traefik/traefik/pull/13344
- https://github.com/traefik/traefik/commit/7ae92d8c2c10ac04ef5a03df0ed5019ce0f44b2d
- https://github.com/traefik/traefik/releases/tag/v2.11.51
- https://github.com/traefik/traefik/releases/tag/v3.6.22
- https://github.com/traefik/traefik/releases/tag/v3.7.6