{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-27889","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","state":"PUBLISHED","assignerShortName":"GitHub_M","dateReserved":"2026-02-24T15:19:29.716Z","datePublished":"2026-03-25T19:36:36.370Z","dateUpdated":"2026-03-25T20:06:31.897Z"},"containers":{"cna":{"title":"NATS: Pre-auth remote server crash via WebSocket frame length overflow in wsRead","problemTypes":[{"descriptions":[{"cweId":"CWE-190","lang":"en","description":"CWE-190: Integer Overflow or Wraparound","type":"CWE"}]}],"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"}}],"references":[{"name":"https://github.com/nats-io/nats-server/security/advisories/GHSA-pq2q-rcw4-3hr6","tags":["x_refsource_CONFIRM"],"url":"https://github.com/nats-io/nats-server/security/advisories/GHSA-pq2q-rcw4-3hr6"},{"name":"https://advisories.nats.io/CVE/secnote-2026-03.txt","tags":["x_refsource_MISC"],"url":"https://advisories.nats.io/CVE/secnote-2026-03.txt"}],"affected":[{"vendor":"nats-io","product":"nats-server","versions":[{"version":">= 2.2.0, < 2.11.14","status":"affected"},{"version":">= 2.12.0, < 2.12.5","status":"affected"}]}],"providerMetadata":{"orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M","dateUpdated":"2026-03-25T19:36:36.370Z"},"descriptions":[{"lang":"en","value":"NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Starting in version 2.2.0 and prior to versions 2.11.14 and 2.12.5, a missing sanity check on a WebSockets frame could trigger a server panic in the nats-server.  This happens before authentication, and so is exposed to anyone who can connect to the websockets port. Versions 2.11.14 and 2.12.5 contains a fix. A workaround is available. The vulnerability only affects deployments which use WebSockets and which expose the network port to untrusted end-points. If one is able to do so, a defense in depth of restricting either of these will mitigate the attack."}],"source":{"advisory":"GHSA-pq2q-rcw4-3hr6","discovery":"UNKNOWN"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-03-25T20:06:22.827675Z","id":"CVE-2026-27889","options":[{"Exploitation":"poc"},{"Automatable":"yes"},{"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":"2026-03-25T20:06:31.897Z"}}]}}