{"id":"CVE-2026-65601","summary":"Traefik before 3.7.7 Namespace Confusion via HTTPRoute ExtensionRef","details":"Traefik versions 3.7.0 through 3.7.6 contain a namespace confusion vulnerability in the Kubernetes Gateway API provider. When resolving HTTPRoute.spec.rules[].backendRefs[].filters[].extensionRef, Traefik used the backend Service namespace instead of the HTTPRoute namespace. A low-privileged route author holding a ReferenceGrant for a cross-namespace Service could therefore bind a Traefik Middleware from the backend namespace without a separate grant for that middleware, potentially injecting trusted reverse-proxy identity headers into downstream requests. The issue is fixed in version 3.7.7.","aliases":["GHSA-qq9q-x9w4-chhj"],"modified":"2026-07-25T03:56:19.306831560Z","published":"2026-07-22T11:21:47.468Z","database_specific":{"cwe_ids":["CWE-863"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/65xxx/CVE-2026-65601.json","cna_assigner":"VulnCheck"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/65xxx/CVE-2026-65601.json"},{"type":"ADVISORY","url":"https://github.com/traefik/traefik/security/advisories/GHSA-qq9q-x9w4-chhj"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-65601"},{"type":"ADVISORY","url":"https://www.vulncheck.com/advisories/traefik-before-namespace-confusion-via-httproute-extensionref"},{"type":"FIX","url":"https://github.com/traefik/traefik/commit/26c96a3935cafb473f4a5bae1886560d9aa4e4f0"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/traefik/traefik","events":[{"introduced":"04aa6bb4f9776f2ba87e5cd181d250e3610e6419"},{"fixed":"b2c18b1e39fbe2099e4dce927e4e6e56674ede0f"}],"database_specific":{"extracted_events":[{"introduced":"3.7.0"},{"fixed":"3.7.7"}],"source":"AFFECTED_FIELD"}}],"versions":["v3.7.6","v3.7.5","v3.7.4","v3.7.3","v3.7.2","v3.7.1","v3.7.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-65601.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N"}]}