{"id":"CVE-2026-63384","state":"PUBLISHED","title":"Libevent: `evtag_unmarshal_header()` decodes a wire `uint32` length into a signed `int` return value.","description":"Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent has an incorrect integer conversion in event_tagging.c when evtag_unmarshal_header uses evtag_decode_int to decode an attacker-controlled uint32 payload length and returns it as a signed int. Values above INT_MAX become negative or truncated, and evtag_unmarshal_string can use the converted value in allocation sizing, producing a wrapped large allocation request and denial of service. This issue is fixed in versions 2.1.13 and 2.2.2-alpha.","publishedAt":"2026-08-20T17:53:08.417Z","updatedAt":"2026-08-20T19:50:32.085Z","severity":{"score":8.7,"label":"High","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["libevent libevent"],"affected":[{"vendor":"libevent","product":"libevent","versions":[{"version":">= 2.2.0-alpha, < 2.2.2-alpha","status":"affected"},{"version":"< 2.1.13","status":"affected"}]}],"references":["https://github.com/libevent/libevent/security/advisories/GHSA-45c6-qx49-89m8","https://github.com/libevent/libevent/commit/109c16499282959d70f56ec3baf4c8b1e6646bda","https://github.com/libevent/libevent/commit/5e3c6ebe342b34c5a9bcf48e9a32ad6708b9c416","https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable","https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha"],"weaknesses":["CWE-190"],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/63xxx/CVE-2026-63384.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-63384","state":"PUBLISHED","datePublished":"2026-08-20T17:53:08.417Z","dateUpdated":"2026-08-20T19:50:32.085Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-07-16T17:39:30.171Z"},"containers":{"cna":{"title":"Libevent: `evtag_unmarshal_header()` decodes a wire `uint32` length into a signed `int` return value.","descriptions":[{"lang":"en","value":"Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent has an incorrect integer conversion in event_tagging.c when evtag_unmarshal_header uses evtag_decode_int to decode an attacker-controlled uint32 payload length and returns it as a signed int. Values above INT_MAX become negative or truncated, and evtag_unmarshal_string can use the converted value in allocation sizing, producing a wrapped large allocation request and denial of service. This issue is fixed in versions 2.1.13 and 2.2.2-alpha."}],"affected":[{"vendor":"libevent","product":"libevent","versions":[{"version":">= 2.2.0-alpha, < 2.2.2-alpha","status":"affected"},{"version":"< 2.1.13","status":"affected"}]}],"references":[{"url":"https://github.com/libevent/libevent/security/advisories/GHSA-45c6-qx49-89m8","name":"https://github.com/libevent/libevent/security/advisories/GHSA-45c6-qx49-89m8","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/libevent/libevent/commit/109c16499282959d70f56ec3baf4c8b1e6646bda","name":"https://github.com/libevent/libevent/commit/109c16499282959d70f56ec3baf4c8b1e6646bda","tags":["x_refsource_MISC"]},{"url":"https://github.com/libevent/libevent/commit/5e3c6ebe342b34c5a9bcf48e9a32ad6708b9c416","name":"https://github.com/libevent/libevent/commit/5e3c6ebe342b34c5a9bcf48e9a32ad6708b9c416","tags":["x_refsource_MISC"]},{"url":"https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable","name":"https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable","tags":["x_refsource_MISC"]},{"url":"https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha","name":"https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"HIGH","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":8.7,"baseSeverity":"HIGH","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-190","lang":"en","description":"CWE-190: Integer Overflow or Wraparound","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-08-20T17:53:08.417Z"},"source":{"advisory":"GHSA-45c6-qx49-89m8","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/libevent/libevent/security/advisories/GHSA-45c6-qx49-89m8","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-20T19:50:07.634809Z","id":"CVE-2026-63384","options":[{"Exploitation":"poc"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-08-20T19:50:32.085Z"}}]}}}