{"id":"CVE-2021-28166","url":"https://www.cyber-defence.io/tools/cve/CVE-2021-28166","generatedAt":"2026-10-27T21:18:15.295Z","title":"In Eclipse Mosquitto version 2.0.0 to 2.0.9, if an authenticated client that had connected with MQTT v5 sent a crafted CONNACK message to the broker, a NULL pointer dereference would occur.","description":"In Eclipse Mosquitto version 2.0.0 to 2.0.9, if an authenticated client that had connected with MQTT v5 sent a crafted CONNACK message to the broker, a NULL pointer dereference would occur.","published":"2021-04-07T19:15:12.000Z","lastModified":"2026-06-17T03:45:56.000Z","status":"Modified","sourceIdentifier":"emo@eclipse.org","cvss":{"version":"3.1","score":6.5,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"},"cwe":["CWE-476"],"affected":["eclipse/mosquitto"],"epss":{"score":0.00968,"percentile":0.61587,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.97%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://bugs.eclipse.org/bugs/show_bug.cgi?id=572608","tags":["Issue Tracking","Patch","Vendor Advisory"],"source":"emo@eclipse.org"},{"url":"https://bugs.eclipse.org/bugs/show_bug.cgi?id=572608","tags":["Issue Tracking","Patch","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-28166","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}