{"id":"CVE-2026-58250","state":"PUBLISHED","title":"NATS Server: Pre-auth server crash via double INFO in leafnode handshake","description":"NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.12.8 and 2.11.17, an unauthenticated peer with network access to a leafnode listener with compression enabled could crash the server during the pre-authentication leafnode handshake by sending repeated leafnode INFO protocol messages before authentication and account setup completed. This issue is fixed in versions 2.12.8 and 2.11.17.","publishedAt":"2026-07-08T19:48:55.058Z","updatedAt":"2026-07-09T13:33:45.059Z","severity":{"score":7.5,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","source":"GitHub_M"},"assigner":"GitHub_M","products":["nats-io nats-server"],"affected":[{"vendor":"nats-io","product":"nats-server","versions":[{"version":"< 2.11.17","status":"affected"},{"version":">= 2.12.0-preview.1, < 2.12.8","status":"affected"}]}],"references":["https://github.com/nats-io/nats-server/security/advisories/GHSA-3g5q-cfh2-cq67","https://github.com/nats-io/nats-server/commit/8dcb26eaea78fdcbe96dbee5986d6019fd5cb94a","https://github.com/nats-io/nats-server/commit/fc5fe39177533e9dbdd651d2458285bfae1dde27","https://github.com/nats-io/nats-server/releases/tag/v2.11.17","https://github.com/nats-io/nats-server/releases/tag/v2.12.8"],"weaknesses":["CWE-476"],"ingestedAt":"2026-10-29T20:12:24.861Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/58xxx/CVE-2026-58250.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-58250","state":"PUBLISHED","datePublished":"2026-07-08T19:48:55.058Z","dateUpdated":"2026-07-09T13:33:45.059Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-06-29T21:54:30.330Z"},"containers":{"cna":{"title":"NATS Server: Pre-auth server crash via double INFO in leafnode handshake","descriptions":[{"lang":"en","value":"NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.12.8 and 2.11.17, an unauthenticated peer with network access to a leafnode listener with compression enabled could crash the server during the pre-authentication leafnode handshake by sending repeated leafnode INFO protocol messages before authentication and account setup completed. This issue is fixed in versions 2.12.8 and 2.11.17."}],"affected":[{"vendor":"nats-io","product":"nats-server","versions":[{"version":"< 2.11.17","status":"affected"},{"version":">= 2.12.0-preview.1, < 2.12.8","status":"affected"}]}],"references":[{"url":"https://github.com/nats-io/nats-server/security/advisories/GHSA-3g5q-cfh2-cq67","name":"https://github.com/nats-io/nats-server/security/advisories/GHSA-3g5q-cfh2-cq67","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/nats-io/nats-server/commit/8dcb26eaea78fdcbe96dbee5986d6019fd5cb94a","name":"https://github.com/nats-io/nats-server/commit/8dcb26eaea78fdcbe96dbee5986d6019fd5cb94a","tags":["x_refsource_MISC"]},{"url":"https://github.com/nats-io/nats-server/commit/fc5fe39177533e9dbdd651d2458285bfae1dde27","name":"https://github.com/nats-io/nats-server/commit/fc5fe39177533e9dbdd651d2458285bfae1dde27","tags":["x_refsource_MISC"]},{"url":"https://github.com/nats-io/nats-server/releases/tag/v2.11.17","name":"https://github.com/nats-io/nats-server/releases/tag/v2.11.17","tags":["x_refsource_MISC"]},{"url":"https://github.com/nats-io/nats-server/releases/tag/v2.12.8","name":"https://github.com/nats-io/nats-server/releases/tag/v2.12.8","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":7.5,"baseSeverity":"HIGH","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-476","lang":"en","description":"CWE-476: NULL Pointer Dereference","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-07-08T19:48:55.058Z"},"source":{"advisory":"GHSA-3g5q-cfh2-cq67","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-07-09T13:33:35.375405Z","id":"CVE-2026-58250","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":"2026-07-09T13:33:45.059Z"}}]}}}