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

What is CVE-2026-29054?

CVE-2026-29054 is a high-severity vulnerability in Traefik Traefik, published on 5 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

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.

Weakness: CWE-178

Which versions are affected by CVE-2026-29054?

7 open source packages ship an affected version, including github.com/traefik/traefik/v2, github.com/traefik/traefik and github.com/traefik/traefik/v3. It affects 1 product.

Products include Traefik Traefik.

How do I fix CVE-2026-29054?

Upgrade github.com/traefik/traefik/v2 to 2.11.38 or later.

Is CVE-2026-29054 being exploited?

There is no known exploitation of CVE-2026-29054 in the wild and no public exploit code.

Other vulnerabilities in Traefik Traefik

• CVE-2024-45410 HTTP client can remove the X-Forwarded headers in Traefik Critical 9.8
• CVE-2026-88877 Traefik v3.7.0 Authentication Bypass via from-to-www-redirect Critical 9.3
• CVE-2026-85595 Traefik before v2.11.55 and v3.0.0 through v3.7.10 Authentication Bypass via digestAuth Critical 9.3
• CVE-2026-88007 Traefik HTTP/3 Backend NTLM Connection Reuse Critical 9.1
• CVE-2026-88009 Traefik: Rootless HTTP/1 request-target routes as "/" but is forwarded verbatim, bypassing path-scoped routing, middleware guards and access logging High 8.8

All Traefik Traefik vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as CLEANSTART-2026-HF02627, GHSA-92mv-8f8w-wq52, GO-2026-4597, MINI-4345-5956-748p, MINI-5h9q-fmqj-99q7.