CVE-2020-13821

5.4 mediumEPSS 0.5%

Medium (5.4) in hivemq broker control center. EPSS 0.5% chance of exploitation in the next 30 days.

An issue was discovered in HiveMQ Broker Control Center 4.3.2. A crafted clientid parameter in an MQTT packet (sent to the Broker) is reflected in the client section of the management console. The attacker's JavaScript is loaded in a browser, which can lead to theft of the session and cookie of the administrator's account of the Broker.

Severity

CVSS 3.1

5.4 medium

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

EPSS: 0.5% chance of exploitation in the next 30 days; higher than 44% of CVEs (scores of 2026-11-01)
CWE: CWE-79
Published: 2020-08-26
Modified: 2026-06-17
Record from: the NVD, synced 2026-10-19

Affected

hivemq:broker_control_center

References

https://payatu.com/advisory/hivemq-mqtt-broker---xss-over-mqtt
https://www.hivemq.com/blog/hivemq-4-3-3-released/
https://payatu.com/advisory/hivemq-mqtt-broker---xss-over-mqtt
https://www.hivemq.com/blog/hivemq-4-3-3-released/

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