{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-63495","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","state":"PUBLISHED","assignerShortName":"GitHub_M","dateReserved":"2026-07-16T21:49:52.069Z","datePublished":"2026-08-20T17:49:16.790Z","dateUpdated":"2026-08-20T19:17:04.616Z"},"containers":{"cna":{"title":"Libevent: Unbounded memory accumulation in WebSocket server via fragmented frames","problemTypes":[{"descriptions":[{"cweId":"CWE-400","lang":"en","description":"CWE-400: Uncontrolled Resource Consumption","type":"CWE"}]},{"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":"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/libevent/libevent/security/advisories/GHSA-qx89-wf2v-vgmx","tags":["x_refsource_CONFIRM"],"url":"https://github.com/libevent/libevent/security/advisories/GHSA-qx89-wf2v-vgmx"},{"name":"https://github.com/libevent/libevent/commit/291c4d1cd75695e898030ebd5c4ddf26c094077b","tags":["x_refsource_MISC"],"url":"https://github.com/libevent/libevent/commit/291c4d1cd75695e898030ebd5c4ddf26c094077b"},{"name":"https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha","tags":["x_refsource_MISC"],"url":"https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha"}],"affected":[{"vendor":"libevent","product":"libevent","versions":[{"version":">= 2.2.0-alpha-dev, < 2.2.2-alpha","status":"affected"}]}],"providerMetadata":{"orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M","dateUpdated":"2026-08-20T17:49:16.790Z"},"descriptions":[{"lang":"en","value":"Libevent is an event notification library. From 2.2.0-alpha-dev until 2.2.2-alpha, the libevent WebSocket server in ws.c accumulates fragmented frames in evws->incomplete_frames without enforcing a total message-size limit. An unauthenticated remote client can repeatedly send fragmented WebSocket frames below WS_MAX_RECV_FRAME_SZ with FIN=0, causing the evbuffer to grow without bound until the process or host exhausts memory. This issue is fixed in version 2.2.2-alpha."}],"source":{"advisory":"GHSA-qx89-wf2v-vgmx","discovery":"UNKNOWN"}},"adp":[{"references":[{"url":"https://github.com/libevent/libevent/security/advisories/GHSA-qx89-wf2v-vgmx","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-20T19:16:58.376889Z","id":"CVE-2026-63495","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":"2026-08-20T19:17:04.616Z"}}]}}