{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-58211","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","state":"PUBLISHED","assignerShortName":"GitHub_M","dateReserved":"2026-06-29T17:09:25.872Z","datePublished":"2026-07-08T20:16:25.262Z","dateUpdated":"2026-07-09T14:27:25.118Z"},"containers":{"cna":{"title":"NATS Server: `no_auth_user` pre-CONNECT fast path bypasses user connection restrictions","problemTypes":[{"descriptions":[{"cweId":"CWE-863","lang":"en","description":"CWE-863: Incorrect Authorization","type":"CWE"}]}],"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"}}],"references":[{"name":"https://github.com/nats-io/nats-server/security/advisories/GHSA-hmmp-q8cx-v964","tags":["x_refsource_CONFIRM"],"url":"https://github.com/nats-io/nats-server/security/advisories/GHSA-hmmp-q8cx-v964"}],"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"}]}],"providerMetadata":{"orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M","dateUpdated":"2026-07-08T20:16:25.262Z"},"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."}],"source":{"advisory":"GHSA-hmmp-q8cx-v964","discovery":"UNKNOWN"}},"adp":[{"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"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-07-09T14:27:25.118Z"}}]}}