{"id":"CVE-2026-85594","state":"PUBLISHED","title":"Traefik v3.7.1 crossProviderNamespaces Bypass via Service Middleware","description":"Traefik versions from v3.7.1 fail to enforce crossProviderNamespaces restrictions on the traefik.ingress.kubernetes.io/service.middlewares Service annotation in the Kubernetes Ingress provider. A namespace-limited tenant excluded from the allowlist can attach an operator-owned middleware to its Service, and if that middleware injects backend credentials, recover them at a controlled backend.","publishedAt":"2026-09-04T11:29:58.771Z","updatedAt":"2026-10-08T15:51:47.581Z","severity":{"score":7,"label":"High","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N","source":"VulnCheck"},"assigner":"VulnCheck","products":["traefik traefik"],"affected":[{"vendor":"traefik","product":"traefik","packageURL":"pkg:golang/github.com/traefik/traefik/v3","defaultStatus":"unaffected","versions":[{"version":"3.7.1","status":"affected","lessThanOrEqual":"3.7.12","versionType":"semver"}]}],"references":["https://github.com/traefik/traefik/security/advisories/GHSA-m6wx-622r-48r9","https://www.vulncheck.com/advisories/traefik-3.7.1-crossprovidernamespaces-bypass-via-service-middleware"],"weaknesses":["CWE-639"],"ingestedAt":"2026-10-29T20:13:15.269Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/85xxx/CVE-2026-85594.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-85594","state":"PUBLISHED","datePublished":"2026-09-04T11:29:58.771Z","dateUpdated":"2026-10-08T15:51:47.581Z","assignerShortName":"VulnCheck","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateReserved":"2026-09-04T10:59:00.162Z"},"containers":{"cna":{"title":"Traefik v3.7.1 crossProviderNamespaces Bypass via Service Middleware","descriptions":[{"lang":"en","value":"Traefik versions from v3.7.1 fail to enforce crossProviderNamespaces restrictions on the traefik.ingress.kubernetes.io/service.middlewares Service annotation in the Kubernetes Ingress provider. A namespace-limited tenant excluded from the allowlist can attach an operator-owned middleware to its Service, and if that middleware injects backend credentials, recover them at a controlled backend."}],"affected":[{"vendor":"traefik","product":"traefik","packageURL":"pkg:golang/github.com/traefik/traefik/v3","defaultStatus":"unaffected","versions":[{"version":"3.7.1","status":"affected","lessThanOrEqual":"3.7.12","versionType":"semver"}]}],"references":[{"url":"https://github.com/traefik/traefik/security/advisories/GHSA-m6wx-622r-48r9","tags":["vendor-advisory"],"name":"GitHub Security Advisory (GHSA-m6wx-622r-48r9)"},{"url":"https://www.vulncheck.com/advisories/traefik-3.7.1-crossprovidernamespaces-bypass-via-service-middleware","name":"VulnCheck Advisory: Traefik v3.7.1 crossProviderNamespaces Bypass via Service Middleware","tags":["third-party-advisory"]}],"metrics":[{"format":"CVSS","cvssV4_0":{"version":"4.0","vectorString":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"LOW","userInteraction":"NONE","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"HIGH","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":7,"baseSeverity":"HIGH"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-639","lang":"en","description":"Authorization Bypass Through User-Controlled Key","type":"CWE"}]}],"providerMetadata":{"shortName":"VulnCheck","orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateUpdated":"2026-10-08T15:51:47.581Z"},"datePublic":"2026-08-21T00:00:00.000Z","cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:*","versionStartIncluding":"3.7.1","versionEndIncluding":"3.7.12"}]}]}],"credits":[{"lang":"en","value":"velgusgus599","type":"reporter"}],"x_generator":{"engine":"vulncheck-endgame"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-08T14:47:22.510684Z","id":"CVE-2026-85594","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-08T14:47:37.976Z"}}]}}}