Insufficient verification of data authenticity in Traefik - CVE-2026-54764
Published: July 3, 2026
Vulnerability identifier: #VU136876
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-54764
CWE-ID: CWE-345
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Containous
Affected software:
Traefik
Traefik
Detailed vulnerability description
The vulnerability allows a remote attacker to bypass port-based authorization checks.
The vulnerability exists due to insufficient verification of data authenticity in the ForwardAuth middleware when handling requests with a spoofed X-Forwarded-Proto header while trustForwardHeader is set to false. A remote attacker can send a specially crafted request to bypass port-based authorization checks.
Exploitation affects deployments where the downstream authentication service makes authorization decisions based on the X-Forwarded-Port header.
How to mitigate CVE-2026-54764
Install security update from vendor's website.