CVE-2026-29054

CVE-2026-29054 · Traefik: lowercase `Connection` tokens can delete traefik-managed forwarded identity headers (for example, `X-Real-Ip`)

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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.

CVSS 7.5 · High · EPSS 0.5%

Published

2026-03-05T16:18:49.230Z

Updated

2026-07-15T01:10:49.626Z

Stack: web

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