ForwardAuth middleware leaks X-Forwarded-Port spoofing via untrusted X-Forwarded-Proto when trustForwardHeader=false (traefik traefik)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.28 % · percentile 21 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- GitHub_M
- NVD status
- Analyzed
Description
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.
Weaknesses (CWE)
- CWE-345 — Insufficient Verification of Data Authenticity
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 4.0 | MEDIUM 6.9 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N | GitHub_M |
| CVSS 4.0 | MEDIUM 6.9 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X | NVD · security-advisories@github.com (Secondary) |
| CVSS 3.1 | MEDIUM 5.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N | NVD · nvd@nist.gov (Primary) |
Advisories
- GHSA-3q9r-p662-5j8m — Traefik: ForwardAuth middleware leaks X-Forwarded-Port spoofing via untrusted X-Forwarded-Proto when trustForwardHeader=false
- GO-2026-6202 — Traefik: ForwardAuth middleware leaks X-Forwarded-Port spoofing via untrusted X-Forwarded-Proto when trustForwardHeader=false in github.com/traefik/traefik
European references
- ENISA EUVD · EUVD-2026-41937
- GCVE · GCVE-0-2026-54764
CERT-FR advisories
- CERTFR-2026-AVI-0823 — Multiples vulnérabilités dans Traefik · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:*< 2.11.51cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:*≥ 3.0.0 < 3.6.22cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:*≥ 3.7.0 < 3.7.6
Affected products
| Product | Versions |
|---|---|
| traefik · traefik | affected < 2.11.51 ; affected >= 3.0.0, < 3.6.22 ; affected >= 3.7.0, < 3.7.6 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |