{"id":"CVE-2021-41039","aliases":["BELL-CVE-2021-41039","DEBIAN-CVE-2021-41039","EUVD-2021-28191","GHSA-5xp2-36v8-r67m","OESA-2022-1498","UBUNTU-CVE-2021-41039","USN-6492-1"],"status":"published","title":"In versions 1.6 to 2.0.11 of Eclipse Mosquitto, an MQTT v5 client connecting with a large number...","description":"In versions 1.6 to 2.0.11 of Eclipse Mosquitto, an MQTT v5 client connecting with a large number of user-property properties could cause excessive CPU usage, leading to a loss of performance and possible denial of service.","severity":{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-12","score":0.01355,"percentile":0.72029,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-1050"],"published":"2021-12-01T00:00:00Z","modified":"2026-10-24T10:30:25Z","fixes":[{"ecosystem":"Debian:12","package":"mosquitto","fixed_in":["2.0.11-1.2"],"sources":["osv"]},{"ecosystem":"Debian:13","package":"mosquitto","fixed_in":["2.0.11-1.2"],"sources":["osv"]},{"ecosystem":"Debian:14","package":"mosquitto","fixed_in":["2.0.11-1.2"],"sources":["osv"]},{"ecosystem":"openEuler:20.03-LTS-SP1","package":"mosquitto","fixed_in":["1.6.15-5.oe1"],"sources":["osv"]},{"ecosystem":"openEuler:20.03-LTS-SP2","package":"mosquitto","fixed_in":["1.6.15-5.oe1"],"sources":["osv"]},{"ecosystem":"openEuler:20.03-LTS-SP3","package":"mosquitto","fixed_in":["1.6.15-5.oe1"],"sources":["osv"]},{"ecosystem":"Ubuntu:Pro:20.04:LTS","package":"mosquitto","fixed_in":["1.6.9-1ubuntu0.1~esm1"],"sources":["osv"]},{"ecosystem":"Ubuntu:22.04:LTS","package":"mosquitto","fixed_in":["2.0.11-1ubuntu1.1"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Debian:12","package":"mosquitto","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.0.11-1.2"}]}]},{"source":"osv","ecosystem":"Debian:13","package":"mosquitto","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.0.11-1.2"}]}]},{"source":"osv","ecosystem":"Debian:14","package":"mosquitto","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.0.11-1.2"}]}]},{"source":"osv","ecosystem":"openEuler:20.03-LTS-SP1","package":"mosquitto","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.6.15-5.oe1"}]}]},{"source":"osv","ecosystem":"openEuler:20.03-LTS-SP2","package":"mosquitto","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.6.15-5.oe1"}]}]},{"source":"osv","ecosystem":"openEuler:20.03-LTS-SP3","package":"mosquitto","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.6.15-5.oe1"}]}]},{"source":"osv","ecosystem":"Ubuntu:Pro:20.04:LTS","package":"mosquitto","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.6.9-1ubuntu0.1~esm1"}]}],"versions":["1.6.6-1","1.6.7-1","1.6.8-1","1.6.8-2","1.6.9-1~build1","1.6.9-1"]},{"source":"osv","ecosystem":"Ubuntu:22.04:LTS","package":"mosquitto","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.0.11-1ubuntu1.1"}]}],"versions":["2.0.11-1","2.0.11-1build1","2.0.11-1ubuntu1"]},{"source":"osv","ecosystem":"Ubuntu:Pro:20.04:LTS","package":"mosquitto","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.6.9-1ubuntu0.1~esm1"}]}],"versions":["1.6.6-1","1.6.7-1","1.6.8-1","1.6.8-2","1.6.9-1~build1","1.6.9-1"],"bundled":6},{"source":"osv","ecosystem":"Ubuntu:22.04:LTS","package":"mosquitto","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.0.11-1ubuntu1.1"}]}],"versions":["2.0.11-1","2.0.11-1build1","2.0.11-1ubuntu1"],"bundled":6}],"products":[{"vendor":"eclipse","product":"mosquitto"},{"vendor":"the eclipse foundation","product":"eclipse mosquitto"}],"references":[{"url":"https://bugs.eclipse.org/bugs/show_bug.cgi?id=575314","tags":["x_transferred","Exploit","Issue Tracking","Patch","Vendor Advisory","fix","report"]},{"url":"https://www.debian.org/security/2023/dsa-5511","tags":["vendor-advisory","x_transferred","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-41039","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-5xp2-36v8-r67m"},{"url":"https://docs.bell-sw.com/security/cves/CVE-2021-41039","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2021-41039","tags":["advisory"]},{"url":"https://www.openeuler.org/en/security/safety-bulletin/detail.html?id=openEuler-SA-2022-1498","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2021-41039","tags":["report"]},{"url":"https://ubuntu.com/security/notices/USN-6492-1","tags":["advisory"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2021-41039","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2021-34431","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2021-34434","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2023-0809","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2023-3592","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2023-28366","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2021-41039","description":"In versions 1.6 to 2.0.11 of Eclipse Mosquitto, an MQTT v5 client connecting with a large number of user-property properties could cause excessive CPU usage, leading to a loss of performance and possible denial of service.","status":"published","published":"2021-12-01T00:00:00Z","modified":"2024-08-04T02:59:31.087Z","cwes":["CWE-1050"],"updated_at":"2026-11-02T14:32:59.105382Z"}],"euvd":[{"id":"EUVD-2021-28191","description":"In versions 1.6 to 2.0.11 of Eclipse Mosquitto, an MQTT v5 client connecting with a large number of user-property properties could cause excessive CPU usage, leading to a loss of performance and possible denial of service.","status":"published","published":"2021-12-01T00:00:00Z","modified":"2024-08-04T02:59:31Z","updated_at":"2026-11-03T03:24:19.242491Z"}],"ghsa":[{"id":"GHSA-5xp2-36v8-r67m","title":"In versions 1.6 to 2.0.11 of Eclipse Mosquitto, an MQTT v5 client connecting with a large number...","description":"In versions 1.6 to 2.0.11 of Eclipse Mosquitto, an MQTT v5 client connecting with a large number of user-property properties could cause excessive CPU usage, leading to a loss of performance and possible denial of service.","status":"published","published":"2021-12-02T00:00:36Z","modified":"2023-10-11T05:03:56Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-1050"],"updated_at":"2026-11-02T14:54:47.501822Z"}],"nvd":[{"id":"CVE-2021-41039","description":"In versions 1.6 to 2.0.11 of Eclipse Mosquitto, an MQTT v5 client connecting with a large number of user-property properties could cause excessive CPU usage, leading to a loss of performance and possible denial of service.","status":"published","published":"2021-12-01T20:15:07.933Z","modified":"2026-06-17T04:07:47.517Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"primary"},{"version":"2.0","score":5,"vector":"AV:N/AC:L/Au:N/C:N/I:N/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-1050"],"updated_at":"2026-11-02T14:07:01.811115Z"}],"osv":[{"id":"BELL-CVE-2021-41039","title":"CVE-2021-41039 does not affect BellSoft software","status":"withdrawn","published":"2021-12-01T20:15:00Z","modified":"2026-01-26T09:46:03.599133Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T15:28:16.5265Z"},{"id":"CVE-2021-41039","description":"In versions 1.6 to 2.0.11 of Eclipse Mosquitto, an MQTT v5 client connecting with a large number of user-property properties could cause excessive CPU usage, leading to a loss of performance and possible denial of service.","status":"published","published":"2021-12-01T20:15:07.933Z","modified":"2026-10-24T10:30:25.691166855Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T15:44:21.249056Z"},{"id":"DEBIAN-CVE-2021-41039","description":"In versions 1.6 to 2.0.11 of Eclipse Mosquitto, an MQTT v5 client connecting with a large number of user-property properties could cause excessive CPU usage, leading to a loss of performance and possible denial of service.","status":"published","published":"2021-12-01T20:15:07.933Z","modified":"2026-10-23T18:03:27.873708537Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T15:45:35.521549Z"},{"id":"OESA-2022-1498","title":"mosquitto security update","description":"Mosquitto is an open source message broker that implements the MQ Telemetry Transport protocol version 3.1 and 3.1.1 MQTT provides a lightweight method of carrying out messaging using a publish/subscribe model. This makes it suitable for \u0026quot;machine to machine\u0026quot; messaging such as with low power sensors or mobile devices such as phones, embedded computers or micro-controllers like the Arduino.\r\n\r\nSecurity Fix(es):\r\n\r\nIn versions 1.6 to 2.0.11 of Eclipse Mosquitto, an MQTT v5 client connecting with a large number of user-property properties could cause excessive CPU usage, leading to a loss of performance and possible denial of service.(CVE-2021-41039)","status":"published","published":"2022-01-22T11:04:46Z","modified":"2026-08-18T01:16:19.825176245Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T15:52:38.987987Z"},{"id":"UBUNTU-CVE-2021-41039","description":"In versions 1.6 to 2.0.11 of Eclipse Mosquitto, an MQTT v5 client connecting with a large number of user-property properties could cause excessive CPU usage, leading to a loss of performance and possible denial of service.","status":"published","published":"2021-12-01T20:15:00Z","modified":"2026-04-22T13:00:47.404883Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T15:54:29.220315Z"},{"id":"USN-6492-1","title":"mosquitto vulnerabilities","description":"Kathrin Kleinhammer discovered that Mosquitto incorrectly handled certain\ninputs. If a user or an automated system were provided with a specially crafted\ninput, a remote attacker could possibly use this issue to cause a denial of\nservice. This issue only affected Ubuntu 20.04 LTS. (CVE-2021-34431)\n\nZhanxiang Song discovered that Mosquitto incorrectly handled certain inputs. If\na user or an automated system were provided with a specially crafted input, a\nremote attacker could possibly use this issue to cause an authorisation bypass.\nThis issue only affected Ubuntu 22.04 LTS and Ubuntu 23.04. (CVE-2021-34434)\n\nZhanxiang Song, Bin Yuan, DeQing Zou, and Hai Jin discovered that Mosquitto\nincorrectly handled certain inputs. If a user or an automated system were\nprovided with a specially crafted input, a remote attacker could possibly use\nthis issue to cause a denial of service. This issue only affected Ubuntu 20.04\nLTS and Ubuntu 22.04 LTS. (CVE-2021-41039)\n\nZhengjie Du discovered that Mosquitto incorrectly handled certain inputs. If a\nuser or an automated system were provided with a specially crafted input file,\na remote attacker could possibly use this issue to cause a denial of service.\n(CVE-2023-0809)\n\nIt was discovered that Mosquitto incorrectly handled certain inputs. If a user\nor an automated system were provided with a specially crafted input, a remote\nattacker could possibly use this issue to cause a denial of service.\n(CVE-2023-3592)\n\nMischa Bachmann discovered that Mosquitto incorrectly handled certain inputs.\nIf a user or an automated system were provided with a specially crafted input,\na remote attacker could possibly use this issue to cause a denial of service.\nThis issue was only fixed in Ubuntu 22.04 LTS and Ubuntu 23.04.\n(CVE-2023-28366)\n","status":"published","published":"2023-11-21T15:23:51Z","modified":"2026-04-22T10:41:36.101799Z","updated_at":"2026-11-02T16:58:17.305935Z"}]}}