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.
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
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Go | github.com/traefik/traefik | no fix listed | GO-2026-4597 |
| Go | github.com/traefik/traefik/v2 | 2.11.38 | GHSA-92mv-8f8w-wq52 |
| Go | github.com/traefik/traefik/v2 | 2.11.38 | GO-2026-4597 |
| Go | github.com/traefik/traefik/v3 | 3.6.9 | GHSA-92mv-8f8w-wq52 |
| Go | github.com/traefik/traefik/v3 | 3.6.9 | GO-2026-4597 |
Affected products (as reported)
Weakness: CWE-178 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
References
- https://github.com/traefik/traefik/security/advisories/GHSA-92mv-8f8w-wq52 x_refsource_CONFIRM
- https://github.com/traefik/traefik/releases/tag/v2.11.38 x_refsource_MISC
- https://github.com/traefik/traefik/releases/tag/v3.6.9 x_refsource_MISC
- https://access.redhat.com/security/cve/CVE-2026-29054 vdb-entry, x_refsource_REDHAT
- RHBZ#2444872 issue-tracking, x_refsource_REDHAT
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-29054.json x_sadp-csaf-vex
- https://access.redhat.com/errata/RHSA-2026:10175 vendor-advisory, x_refsource_REDHAT