{"id":"CVE-2026-29054","aliases":["GHSA-92mv-8f8w-wq52","GO-2026-4597"],"url":"https://o3.security/vulnerability/CVE-2026-29054","summary":"Traefik: lowercase `Connection` tokens can delete traefik-managed forwarded identity headers (for example, `X-Real-Ip`)","details":"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.","published":"2026-03-05T16:18:49.230Z","modified":"2026-08-07T11:50:51.384218708Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/traefik/traefik/v2","fixedVersion":"2.11.38"},{"ecosystem":"Go","name":"github.com/traefik/traefik/v3","fixedVersion":"3.6.9"}],"fix":null,"references":[{"type":"WEB","url":"https://github.com/traefik/traefik/releases/tag/v2.11.38"},{"type":"WEB","url":"https://github.com/traefik/traefik/releases/tag/v3.6.9"},{"type":"WEB","url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-29054.json"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:10175"},{"type":"ADVISORY","url":"https://access.redhat.com/security/cve/CVE-2026-29054"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/29xxx/CVE-2026-29054.json"},{"type":"ADVISORY","url":"https://github.com/traefik/traefik/security/advisories/GHSA-92mv-8f8w-wq52"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-29054"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2444872"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-07T11:50:51.384218708Z"}}