{"document":{"category":"csaf_vex","csaf_version":"2.0","title":"CVE-2026-48020: Traefik StripPrefix Route-Level Auth Bypass via Path Normalization","publisher":{"category":"vendor","name":"HarborGuard Database","namespace":"https://database.harborguard.co"},"tracking":{"id":"CVE-2026-48020","status":"final","version":"1","initial_release_date":"2026-06-23T19:10:31.557Z","current_release_date":"2026-06-30T03:18:49.489Z","revision_history":[{"date":"2026-06-23T19:10:31.557Z","number":"1","summary":"Initial machine-readable export from HarborGuard."}]},"distribution":{"tlp":{"label":"WHITE"},"text":"Public CVE data; freely redistributable."},"notes":[{"category":"description","text":"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.","title":"CVE description"}],"references":[{"category":"self","summary":"CVE-2026-48020 on HarborGuard Database","url":"https://database.harborguard.co/cve/CVE-2026-48020"},{"category":"external","summary":"CVE Record","url":"https://www.cve.org/CVERecord?id=CVE-2026-48020"},{"category":"external","summary":"https://github.com/traefik/traefik/security/advisories/GHSA-xf64-8mw2-4gr2","url":"https://github.com/traefik/traefik/security/advisories/GHSA-xf64-8mw2-4gr2"},{"category":"external","summary":"https://github.com/traefik/traefik/releases/tag/v2.11.48","url":"https://github.com/traefik/traefik/releases/tag/v2.11.48"},{"category":"external","summary":"https://github.com/traefik/traefik/releases/tag/v3.6.19","url":"https://github.com/traefik/traefik/releases/tag/v3.6.19"},{"category":"external","summary":"https://github.com/traefik/traefik/releases/tag/v3.7.3","url":"https://github.com/traefik/traefik/releases/tag/v3.7.3"}]},"product_tree":{"branches":[{"category":"vendor","name":"traefik","branches":[{"category":"product_name","name":"traefik","branches":[{"category":"product_version","name":">= 3.7.0-ea.1, < 3.7.3","product":{"name":"traefik traefik >= 3.7.0-ea.1, < 3.7.3","product_id":"CSAFPID-1","product_identification_helper":{"cpe":"cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:*"}}},{"category":"product_version","name":">= 3.0.0-beta1, < 3.6.19","product":{"name":"traefik traefik >= 3.0.0-beta1, < 3.6.19","product_id":"CSAFPID-2","product_identification_helper":{"cpe":"cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:*"}}},{"category":"product_version","name":"< 2.11.48","product":{"name":"traefik traefik < 2.11.48","product_id":"CSAFPID-3","product_identification_helper":{"cpe":"cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:*"}}}]}]}]},"vulnerabilities":[{"cve":"CVE-2026-48020","title":"Traefik StripPrefix Route-Level Auth Bypass via Path Normalization","notes":[{"category":"description","text":"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.","title":"CVE description"}],"product_status":{"known_affected":["CSAFPID-1","CSAFPID-2","CSAFPID-3"]},"scores":[{"cvss_v3":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","baseScore":9.1,"baseSeverity":"CRITICAL"},"products":["CSAFPID-1","CSAFPID-2","CSAFPID-3"]}],"remediations":[{"category":"none_available","details":"No fixed version is published yet. Monitor the upstream advisory.","product_ids":["CSAFPID-1","CSAFPID-2","CSAFPID-3"]}]}]}