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Vulnerability · Published Mar 5, 2026 · Assigned by GitHub_M

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

High 7.5

In plain English

A high-severity security flaw in traefik from traefik. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 45% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.5High
Exploit odds (30 days)0.5%top 55.0% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Gogithub.com/traefik/traefikno fix listedGO-2026-4597
Gogithub.com/traefik/traefik/v22.11.38GHSA-92mv-8f8w-wq52
Gogithub.com/traefik/traefik/v22.11.38GO-2026-4597
Gogithub.com/traefik/traefik/v33.6.9GHSA-92mv-8f8w-wq52
Gogithub.com/traefik/traefik/v33.6.9GO-2026-4597

Affected products (as reported)

VendorProductVersions
traefik traefik >= 2.11.9, < 2.11.38>= 3.1.3, < 3.6.9

Weakness: CWE-178 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

References