CVE-2026-35051
Authentication Bypass in Traefik Reverse Proxy
Publication date: 2026-04-30
Last updated on: 2026-05-01
Assigner: GitHub, Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| traefik | traefik | 3.7.0 |
| traefik | traefik | 3.7.0 |
| traefik | traefik | to 2.11.43 (exc) |
| traefik | traefik | From 3.0.0 (inc) to 3.6.14 (exc) |
| traefik | traefik | 3.7.0 |
| traefik | traefik | 3.7.0 |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-345 | The product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability is an authentication bypass issue in Traefik's ForwardAuth middleware. It occurs when the configuration option trustForwardHeader is set to false and Traefik is deployed behind a trusted upstream proxy. This means that under these conditions, unauthorized users might bypass authentication checks.
How can this vulnerability impact me? :
The impact of this vulnerability is that attackers could potentially access protected resources without proper authentication. This could lead to unauthorized access to sensitive data or services that are supposed to be secured by Traefik's authentication mechanisms.
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability, you should upgrade Traefik to one of the patched versions: 2.11.43, 3.6.14, or 3.7.0-rc.2.
Additionally, review your ForwardAuth middleware configuration, especially the trustForwardHeader setting, and ensure it is properly configured when Traefik is deployed behind a trusted upstream proxy.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
The vulnerability is an authentication bypass in Traefik's ForwardAuth middleware when certain configurations are used. Such an authentication bypass could potentially allow unauthorized access to protected resources.
Unauthorized access due to this vulnerability may lead to non-compliance with standards and regulations like GDPR and HIPAA, which require strict access controls and protection of sensitive data.
However, the provided information does not explicitly describe the impact on compliance with these standards.