CVE-2021-41039
CVSS v3
7.5
HIGH
EPSS Score
1.4 %
exploit probability, as of 2026-09-25
CISA KEV
No
known exploited
Exploitation
—
SSVC status
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.
Technical details
- Published
- 2021-12-01
Frequently asked questions
What is CVE-2021-41039?
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.
Is CVE-2021-41039 actively exploited?
Active exploitation of CVE-2021-41039 has not been confirmed. Its EPSS score was 1.4% on 2026-09-25, the estimated probability of exploitation in the next 30 days.
What is the CVSS score for CVE-2021-41039?
CVE-2021-41039 has a CVSS v3 base score of 7.5 (HIGH severity).
Is CVE-2021-41039 affecting your environment?
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