{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-33219","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","state":"PUBLISHED","assignerShortName":"GitHub_M","dateReserved":"2026-03-17T23:23:58.314Z","datePublished":"2026-03-25T19:55:28.363Z","dateUpdated":"2026-03-25T20:10:35.721Z"},"containers":{"cna":{"title":"NATS is vulnerable to pre-auth DoS through WebSockets client service","problemTypes":[{"descriptions":[{"cweId":"CWE-770","lang":"en","description":"CWE-770: Allocation of Resources Without Limits or Throttling","type":"CWE"}]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"LOW","baseScore":5.3,"baseSeverity":"MEDIUM","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:L","version":"3.1"}}],"references":[{"name":"https://github.com/nats-io/nats-server/security/advisories/GHSA-8r68-gvr4-jh7j","tags":["x_refsource_CONFIRM"],"url":"https://github.com/nats-io/nats-server/security/advisories/GHSA-8r68-gvr4-jh7j"},{"name":"https://advisories.nats.io/CVE/secnote-2026-02.txt","tags":["x_refsource_MISC"],"url":"https://advisories.nats.io/CVE/secnote-2026-02.txt"},{"name":"https://advisories.nats.io/CVE/secnote-2026-11.txt","tags":["x_refsource_MISC"],"url":"https://advisories.nats.io/CVE/secnote-2026-11.txt"},{"name":"https://github.com/advisories/GHSA-qrvq-68c2-7grw","tags":["x_refsource_MISC"],"url":"https://github.com/advisories/GHSA-qrvq-68c2-7grw"}],"affected":[{"vendor":"nats-io","product":"nats-server","versions":[{"version":"< 2.11.15","status":"affected"},{"version":">= 2.12.0-RC.1, < 2.12.6","status":"affected"}]}],"providerMetadata":{"orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M","dateUpdated":"2026-03-25T19:55:28.363Z"},"descriptions":[{"lang":"en","value":"NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Prior to versions 2.11.15 and 2.12.6, a malicious client which can connect to the WebSockets port can cause unbounded memory use in the nats-server before authentication; this requires sending a corresponding amount of data. This is a milder variant of CVE-2026-27571. That earlier issue was a compression bomb, this vulnerability is not. Attacks against this new issue thus require significant client bandwidth. Versions 2.11.15 and 2.12.6 contain a fix. As a workaround, disable websockets if not required for project deployment."}],"source":{"advisory":"GHSA-8r68-gvr4-jh7j","discovery":"UNKNOWN"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-03-25T20:10:18.603979Z","id":"CVE-2026-33219","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":"2026-03-25T20:10:35.721Z"}}]}}