{"id":"CVE-2026-22045","state":"PUBLISHED","title":"Traefik's ACME TLS-ALPN fast path lacks timeouts and close on handshake stall","description":"Traefik is an HTTP reverse proxy and load balancer. Prior to 2.11.35 and 3.6.7, there is a potential vulnerability in Traefik ACME TLS certificates' automatic generation: the ACME TLS-ALPN fast path can allow unauthenticated clients to tie up go routines and file descriptors indefinitely when the ACME TLS challenge is enabled. A malicious client can open many connections, send a minimal ClientHello with acme-tls/1, then stop responding, leading to denial of service of the entry point. The vulnerability is fixed in 2.11.35 and 3.6.7.","publishedAt":"2026-01-15T22:44:05.423Z","updatedAt":"2026-01-20T16:29:37.648Z","severity":{"score":5.9,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","source":"GitHub_M"},"assigner":"GitHub_M","products":["traefik traefik"],"affected":[{"vendor":"traefik","product":"traefik","versions":[{"version":"< 2.11.35","status":"affected"},{"version":">=3.0.0-beta1, < 3.6.7","status":"affected"}]}],"references":["https://github.com/traefik/traefik/security/advisories/GHSA-cwjm-3f7h-9hwq","https://github.com/traefik/traefik/commit/e9f3089e9045812bcf1b410a9d40568917b26c3d","https://github.com/traefik/traefik/releases/tag/v2.11.35","https://github.com/traefik/traefik/releases/tag/v3.6.7"],"weaknesses":["CWE-770"],"ingestedAt":"2026-10-29T20:11:21.040Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/22xxx/CVE-2026-22045.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-22045","state":"PUBLISHED","datePublished":"2026-01-15T22:44:05.423Z","dateUpdated":"2026-01-20T16:29:37.648Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-01-05T22:30:38.720Z"},"containers":{"cna":{"title":"Traefik's ACME TLS-ALPN fast path lacks timeouts and close on handshake stall","descriptions":[{"lang":"en","value":"Traefik is an HTTP reverse proxy and load balancer. Prior to 2.11.35 and 3.6.7, there is a potential vulnerability in Traefik ACME TLS certificates' automatic generation: the ACME TLS-ALPN fast path can allow unauthenticated clients to tie up go routines and file descriptors indefinitely when the ACME TLS challenge is enabled. A malicious client can open many connections, send a minimal ClientHello with acme-tls/1, then stop responding, leading to denial of service of the entry point. The vulnerability is fixed in 2.11.35 and 3.6.7."}],"affected":[{"vendor":"traefik","product":"traefik","versions":[{"version":"< 2.11.35","status":"affected"},{"version":">=3.0.0-beta1, < 3.6.7","status":"affected"}]}],"references":[{"url":"https://github.com/traefik/traefik/security/advisories/GHSA-cwjm-3f7h-9hwq","name":"https://github.com/traefik/traefik/security/advisories/GHSA-cwjm-3f7h-9hwq","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/traefik/traefik/commit/e9f3089e9045812bcf1b410a9d40568917b26c3d","name":"https://github.com/traefik/traefik/commit/e9f3089e9045812bcf1b410a9d40568917b26c3d","tags":["x_refsource_MISC"]},{"url":"https://github.com/traefik/traefik/releases/tag/v2.11.35","name":"https://github.com/traefik/traefik/releases/tag/v2.11.35","tags":["x_refsource_MISC"]},{"url":"https://github.com/traefik/traefik/releases/tag/v3.6.7","name":"https://github.com/traefik/traefik/releases/tag/v3.6.7","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":5.9,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-770","lang":"en","description":"CWE-770: Allocation of Resources Without Limits or Throttling","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-01-15T22:44:05.423Z"},"source":{"advisory":"GHSA-cwjm-3f7h-9hwq","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-01-20T16:29:14.971395Z","id":"CVE-2026-22045","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-01-20T16:29:37.648Z"}}]}}}