{"schemaVersion":3,"id":"USN-8840-1","aliases":[],"status":"published","duplicateOf":null,"title":null,"description":"libevent vulnerabilities\n\nMichał Majchrowicz and Marcin Wyczechowski discovered that libevent\nincorrectly handled certain DNS responses. A remote attacker could possibly\nuse this issue to cause a denial of service or execute arbitrary code.\n(CVE-2026-63387)\n\nIt was discovered that libevent incorrectly handled certain connections. A\nlocal attacker could possibly use this issue to cause a denial of service\nor execute arbitrary code. This issue only affected Ubuntu 18.04 LTS,\nUbuntu 20.04 LTS, Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, and Ubuntu 26.04 LTS.\n(CVE-2026-63388)","dates":{"published":"2026-09-28T20:05:19.000Z","modified":"2026-09-29T23:56:46.660Z","reserved":null,"kevAdded":[],"kevDue":[]},"cvss":{"headline":{"score":null,"severity":"unknown","version":null,"versionLabel":null,"source":null,"vector":null,"computed":false,"selection":"none"},"metrics":[]},"epss":{"probability":null,"percentile":null,"severity":"unknown","asOf":null,"change":{"pp":null,"baselineDate":null,"baselineScore":null},"history":[],"last30":[]},"kev":{"state":"not-listed","entries":[],"listedCount":0,"totalCatalogs":3,"catalogs":[{"source":"cisa","label":"CISA","listed":false,"entry":null},{"source":"enisa","label":"ENISA","listed":false,"entry":null},{"source":"circl","label":"CIRCL","listed":false,"entry":null}]},"ransomware":{"state":"none-recorded","sources":[]},"exploits":[],"exploitCount":0,"weaknesses":[],"affected":[{"vendor":"ubuntu","product":"libevent","name":"libevent","label":"libevent","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/libevent","purlType":"deb","versions":[{"text":"< 2.0.21-stable-1ubuntu1.14.04.2+esm2","noFixRecorded":false,"fixedIn":null},{"text":"< 2.0.21-stable-2ubuntu0.16.04.1+esm2","noFixRecorded":false,"fixedIn":null},{"text":"< 2.1.8-stable-4ubuntu0.1~esm2","noFixRecorded":false,"fixedIn":null},{"text":"< 2.1.11-stable-1ubuntu0.1~esm2","noFixRecorded":false,"fixedIn":null},{"text":"< 2.1.12-stable-1ubuntu0.2","noFixRecorded":false,"fixedIn":null},{"text":"< 2.1.12-stable-9ubuntu2.2","noFixRecorded":false,"fixedIn":null},{"text":"< 2.1.12-stable-10ubuntu0.2","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 2.0.21-stable-1ubuntu1.14.04.2+esm2 | < 2.0.21-stable-2ubuntu0.16.04.1+esm2 | < 2.1.8-stable-4ubuntu0.1~esm2 | < 2.1.11-stable-1ubuntu0.1~esm2 | < 2.1.12-stable-1ubuntu0.2 | < 2.1.12-stable-9ubuntu2.2 | < 2.1.12-stable-10ubuntu0.2","eol":null,"hubHref":null}],"affectedCount":1,"eol":{"hasEol":false,"count":0},"references":[{"url":"https://ubuntu.com/security/notices/USN-8840-1","label":"ubuntu.com/security/notices/USN-8840-1","hostname":"ubuntu.com","tags":["Advisory"]},{"url":"https://ubuntu.com/security/CVE-2026-63387","label":"ubuntu.com/security/CVE-2026-63387","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://ubuntu.com/security/CVE-2026-63388","label":"ubuntu.com/security/CVE-2026-63388","hostname":"ubuntu.com","tags":["REPORT"]}],"lineage":{"upstream":["CVE-2026-63387","CVE-2026-63388"],"downstream":[],"duplicates":[],"related":["CVE-2026-63387","CVE-2026-63388"]},"timeline":[{"kind":"published","date":"2026-09-28T20:05:19.000Z","label":"Published","detail":"Vulnerability first disclosed.","source":null},{"kind":"modified","date":"2026-09-29T23:56:46.660Z","label":"Last modified","detail":"Vulnerability information updated.","source":null}],"risk":{"score":0,"level":"minimal","profile":"Default","thresholds":{"critical":75,"high":50,"medium":25,"low":10}},"meta":{"dataAsOf":"2026-10-21T06:57:22.201Z","stale":false,"partial":false}}