CVE-2026-54764
Description
A flaw was found in Traefik, an HTTP reverse proxy and load balancer. The ForwardAuth middleware, even when configured to not trust forwarded headers, incorrectly uses the original incoming request to determine the X-Forwarded-Port header sent to the authentication service. This allows an unauthenticated remote attacker to inject a false X-Forwarded-Proto: https header over a plain HTTP connection, leading Traefik to forward X-Forwarded-Port: 443 to the authentication service. This bypasses port-based authorization checks, potentially granting unauthorized access.
Statement
Moderate: A flaw in Traefik's ForwardAuth middleware, as used in Red Hat OpenShift Dev Spaces, allows an unauthenticated remote attacker to bypass port-based authorization. By injecting a forged X-Forwarded-Proto header over an HTTP connection, an attacker can cause the authentication service to receive an incorrect X-Forwarded-Port value, leading to unauthorized access.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.8 | 5.8 | N/A |
| Attack Vector | Network | Network | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | None | None | N/A |
| User Interaction | None | None | N/A |
| Scope | Changed | Changed | N/A |
| Confidentiality | None | None | N/A |
| Integrity Impact | Low | Low | N/A |
| Availability Impact | None | None | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
Understanding the Weakness (CWE)
Access Control
Technical Impact: Bypass Protection Mechanism; Gain Privileges or Assume Identity
An attacker could utilize the untrusted data source to bypass protection mechanisms and gain access to sensitive data.
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