{"cve":"CVE-2026-88004","nvd":{"published":"2026-09-10T15:17:54.940","modified":"2026-09-14T19:58:45.057","status":"Analyzed","description":"Traefik is an open source HTTP reverse proxy and load balancer. From 3.2.0 until 3.7.13, Traefik entrypoint defenses aliasHeadersStrategy, underscoreHeadersStrategy, and forwardedHeaders inspect req.Header but not req.Trailer, allowing an unauthenticated client to submit an aliasing or trusted header name in an HTTP/1.1 chunked trailer or an HTTP/2 trailer. When the retry or buffering middleware reads the body before the reverse proxy clones the request, the attacker-controlled trailer value reaches a backend that merges trailers into the header namespace, bypassing the documented delete or reject behavior and potentially spoofing identity or forwarded routing data. This issue is fixed in 3.7.13.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N","score":7.0},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","score":7.4},"cwes":["CWE-436","CWE-807"],"references":["https://github.com/traefik/traefik/commit/55bbda4f65e0f9c533c870983a767a7081126db7","https://github.com/traefik/traefik/pull/13822","https://github.com/traefik/traefik/releases/tag/v3.7.13","https://github.com/traefik/traefik/security/advisories/GHSA-v67p-phpq-fc8x"],"products":["traefik:traefik"],"source":"nvd","synced_at":"2026-10-19T22:52:53.108888569+00:00"},"epss":{"cve":"CVE-2026-88004","score":0.00452,"percentile":0.39296,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-v67p-phpq-fc8x","url":"https://osv.dev/vulnerability/GHSA-v67p-phpq-fc8x","summary":"Traefik entrypoint header-name sanitization bypassed via request trailers","modified":"2026-09-17T17:40:53.498080005Z","packages":[{"ecosystem":"Go","name":"github.com/traefik/traefik/v3","purl":"pkg:golang/github.com/traefik/traefik/v3","ranges":[">=3.2.0 <3.7.13"],"fixed":["3.7.13"]}]},{"id":"GO-2026-6467","url":"https://osv.dev/vulnerability/GO-2026-6467","summary":"Traefik entrypoint header-name sanitization bypassed via request trailers in github.com/traefik/traefik","modified":"2026-09-17T17:30:12.190610175Z","packages":[{"ecosystem":"Go","name":"github.com/traefik/traefik","purl":"pkg:golang/github.com/traefik/traefik","ranges":["all versions"],"fixed":[]},{"ecosystem":"Go","name":"github.com/traefik/traefik/v2","purl":"pkg:golang/github.com/traefik/traefik/v2","ranges":["all versions"],"fixed":[]},{"ecosystem":"Go","name":"github.com/traefik/traefik/v3","purl":"pkg:golang/github.com/traefik/traefik/v3","ranges":[">=3.2.0 <3.7.13"],"fixed":["3.7.13"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}