ALT-PU-2026-4171

CVE-2026-26998

Traefik is an HTTP reverse proxy and load balancer. Prior to versions 2.11.38 and 3.6.9, there is a potential vulnerability in Traefik managing the ForwardAuth middleware responses. When Traefik is configured to use the ForwardAuth middleware, the response body from the authentication server is read entirely into memory without any size limit. There is no maxResponseBodySize configuration to restrict the amount of data read from the authentication server response. If the authentication server returns an unexpectedly large or unbounded response body, Traefik will allocate unlimited memory, potentially causing an out-of-memory (OOM) condition that crashes the process. This results in a denial of service for all routes served by the affected Traefik instance. This issue has been patched in versions 2.11.38 and 3.6.9.

CVE-2026-26998

Traefik is an HTTP reverse proxy and load balancer. Prior to versions 2.11.38 and 3.6.9, there is a potential vulnerability in Traefik managing the ForwardAuth middleware responses. When Traefik is configured to use the ForwardAuth middleware, the response body from the authentication server is read entirely into memory without any size limit. There is no maxResponseBodySize configuration to restrict the amount of data read from the authentication server response. If the authentication server returns an unexpectedly large or unbounded response body, Traefik will allocate unlimited memory, potentially causing an out-of-memory (OOM) condition that crashes the process. This results in a denial of service for all routes served by the affected Traefik instance. This issue has been patched in versions 2.11.38 and 3.6.9.

CVE-2026-26998

Traefik is an HTTP reverse proxy and load balancer. Prior to versions ...

GHSA-fw45-f5q2-2p4x

Traefik has unbounded io.ReadAll on auth server response body that causes OOM DOS

CVE-2026-29054

Traefik is an HTTP reverse proxy and load balancer. From version 2.11.9 to 2.11.37 and from version 3.1.3 to 3.6.8, there is a potential vulnerability in Traefik managing the Connection header with X-Forwarded headers. When Traefik processes HTTP/1.1 requests, the protection put in place to prevent the removal of Traefik-managed X-Forwarded headers (such as X-Real-Ip, X-Forwarded-Host, X-Forwarded-Port, etc.) via the Connection header does not handle case sensitivity correctly. The Connection tokens are compared case-sensitively against the protected header names, but the actual header deletion operates case-insensitively. As a result, a remote unauthenticated client can use lowercase Connection tokens (e.g. Connection: x-real-ip) to bypass the protection and trigger the removal of Traefik-managed forwarded identity headers. This issue has been patched in versions 2.11.38 and 3.6.9.