Vulnerability in Traefik
CVE-2026-54764
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.
EPSS: 0.002 (14.4th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.8 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N.
Affected products
- Traefik — versions < 2.11.51, >= 3.0.0, < 3.6.22, >= 3.7.0, < 3.7.6
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Patch, Vendor Advisory)
- security-advisories@github.com (x_refsource_MISC, Issue Tracking)
- security-advisories@github.com (Patch, x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-54764?
- CVE-2026-54764 is a medium-severity vulnerability in Traefik, classified under Insufficient Verification of Data Authenticity. CVSS score: 5.8/10. Published 2026-07-06.
- How severe is CVE-2026-54764?
- Medium severity. CVSS v3 base score is 5.8 out of 10.