{"id":"CVE-2026-58211","state":"PUBLISHED","title":"NATS Server: `no_auth_user` pre-CONNECT fast path bypasses user connection restrictions","description":"NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.14.3 and 2.12.12, a client could be registered as the configured no_auth_user through a parser path used when the first client operation was not CONNECT, bypassing user-level connection restrictions such as allowed_connection_types or proxy_required that normal authentication would apply. This issue is fixed in versions 2.14.3 and 2.12.12.","publishedAt":"2026-07-08T20:16:25.262Z","updatedAt":"2026-07-09T14:27:25.118Z","severity":{"score":5.4,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["nats-io nats-server"],"affected":[{"vendor":"nats-io","product":"nats-server","versions":[{"version":"< 2.12.12","status":"affected"},{"version":">= 2.14.0-RC.1, < 2.14.3","status":"affected"}]}],"references":["https://github.com/nats-io/nats-server/security/advisories/GHSA-hmmp-q8cx-v964"],"weaknesses":["CWE-863"],"ingestedAt":"2026-10-29T20:12:24.861Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/58xxx/CVE-2026-58211.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-58211","state":"PUBLISHED","datePublished":"2026-07-08T20:16:25.262Z","dateUpdated":"2026-07-09T14:27:25.118Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-06-29T17:09:25.872Z"},"containers":{"cna":{"title":"NATS Server: `no_auth_user` pre-CONNECT fast path bypasses user connection restrictions","descriptions":[{"lang":"en","value":"NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.14.3 and 2.12.12, a client could be registered as the configured no_auth_user through a parser path used when the first client operation was not CONNECT, bypassing user-level connection restrictions such as allowed_connection_types or proxy_required that normal authentication would apply. This issue is fixed in versions 2.14.3 and 2.12.12."}],"affected":[{"vendor":"nats-io","product":"nats-server","versions":[{"version":"< 2.12.12","status":"affected"},{"version":">= 2.14.0-RC.1, < 2.14.3","status":"affected"}]}],"references":[{"url":"https://github.com/nats-io/nats-server/security/advisories/GHSA-hmmp-q8cx-v964","name":"https://github.com/nats-io/nats-server/security/advisories/GHSA-hmmp-q8cx-v964","tags":["x_refsource_CONFIRM"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":5.4,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"LOW","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-863","lang":"en","description":"CWE-863: Incorrect Authorization","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-07-08T20:16:25.262Z"},"source":{"advisory":"GHSA-hmmp-q8cx-v964","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-07-09T14:27:18.977045Z","id":"CVE-2026-58211","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":"2026-07-09T14:27:25.118Z"}}]}}}