{"id":"CVE-2026-48020","aliases":["GHSA-xf64-8mw2-4gr2","GO-2026-5752"],"url":"https://o3.security/vulnerability/CVE-2026-48020","summary":"Traefik StripPrefix Route-Level Auth Bypass via Path Normalization","details":"Traefik is an HTTP reverse proxy and load balancer. Prior to 2.11.48, 3.6.19, and 3.7.3, there is a high severity vulnerability in Traefik's StripPrefix middleware that allows an unauthenticated attacker to bypass route-level authentication and authorization. When a public router matches on a PathPrefix rule and applies the StripPrefix middleware, a request path containing .. or its percent-encoded form %2e%2e can match the public route at routing time and then, after the prefix is stripped and the path is normalized, resolve to a path served by a separate, authenticated router. As a result, an attacker can reach protected backend paths — such as admin or internal configuration endpoints — without satisfying the authentication middleware attached to the protected router. This vulnerability is fixed in 2.11.48, 3.6.19, and 3.7.3.","published":"2026-06-23T19:10:31.557Z","modified":"2026-08-07T11:50:19.559280262Z","cvss":null,"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/traefik/traefik/v2","fixedVersion":"2.11.48"},{"ecosystem":"Go","name":"github.com/traefik/traefik/v3","fixedVersion":"3.6.19"},{"ecosystem":"Go","name":"github.com/traefik/traefik/v3","fixedVersion":"3.7.3"}],"fix":null,"references":[{"type":"WEB","url":"https://github.com/traefik/traefik/releases/tag/v2.11.48"},{"type":"WEB","url":"https://github.com/traefik/traefik/releases/tag/v3.6.19"},{"type":"WEB","url":"https://github.com/traefik/traefik/releases/tag/v3.7.3"},{"type":"WEB","url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-48020.json"},{"type":"ADVISORY","url":"https://access.redhat.com/security/cve/CVE-2026-48020"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48020.json"},{"type":"ADVISORY","url":"https://github.com/traefik/traefik/security/advisories/GHSA-xf64-8mw2-4gr2"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-48020"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2491915"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-07T11:50:19.559280262Z"}}