{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-33433","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","state":"PUBLISHED","assignerShortName":"GitHub_M","dateReserved":"2026-03-19T18:45:22.436Z","datePublished":"2026-03-27T13:49:08.455Z","dateUpdated":"2026-03-30T12:00:41.940Z"},"containers":{"cna":{"title":"Traefik Vulnerable to BasicAuth/DigestAuth Identity Spoofing via Non-Canonical headerField","problemTypes":[{"descriptions":[{"cweId":"CWE-290","lang":"en","description":"CWE-290: Authentication Bypass by Spoofing","type":"CWE"}]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"HIGH","attackRequirements":"PRESENT","privilegesRequired":"HIGH","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"HIGH","subIntegrityImpact":"HIGH","subAvailabilityImpact":"NONE","baseScore":5.1,"baseSeverity":"MEDIUM","vectorString":"CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N","version":"4.0"}}],"references":[{"name":"https://github.com/traefik/traefik/security/advisories/GHSA-qr99-7898-vr7c","tags":["x_refsource_CONFIRM"],"url":"https://github.com/traefik/traefik/security/advisories/GHSA-qr99-7898-vr7c"},{"name":"https://github.com/traefik/traefik/releases/tag/v2.11.42","tags":["x_refsource_MISC"],"url":"https://github.com/traefik/traefik/releases/tag/v2.11.42"},{"name":"https://github.com/traefik/traefik/releases/tag/v3.6.11","tags":["x_refsource_MISC"],"url":"https://github.com/traefik/traefik/releases/tag/v3.6.11"},{"name":"https://github.com/traefik/traefik/releases/tag/v3.7.0-ea.3","tags":["x_refsource_MISC"],"url":"https://github.com/traefik/traefik/releases/tag/v3.7.0-ea.3"}],"affected":[{"vendor":"traefik","product":"traefik","versions":[{"version":"< 2.11.42","status":"affected"},{"version":">= 3.0.0-beta1, < 3.6.11","status":"affected"},{"version":">= 3.7.0-ea.1, < 3.7.0-ea.3","status":"affected"}]}],"providerMetadata":{"orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M","dateUpdated":"2026-03-27T13:49:08.455Z"},"descriptions":[{"lang":"en","value":"Traefik is an HTTP reverse proxy and load balancer. Prior to versions 2.11.42, 3.6.11, and 3.7.0-ea.3, when `headerField` is configured with a non-canonical HTTP header name (e.g., `x-auth-user` instead of `X-Auth-User`), an authenticated attacker can inject their own canonical version of that header to impersonate any identity to the backend. The backend receives two header entries — the attacker-injected canonical one is read first, overriding Traefik's non-canonical write. Versions 2.11.42, 3.6.11, and 3.7.0-ea.3 patch the issue."}],"source":{"advisory":"GHSA-qr99-7898-vr7c","discovery":"UNKNOWN"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-03-30T12:00:28.784939Z","id":"CVE-2026-33433","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-03-30T12:00:41.940Z"}}]}}