Published:2026/04/24  Last Updated:2026/04/24

JVN#20669184
Apache ActiveMQ series improper validation of MQTT packets [AMQ-9810]

Overview

Apache ActiveMQ series provided by The Apache Software Foundation does not properly validate MQTT packets.

Products Affected

  • Apache ActiveMQ 5.x versions prior to 5.19.2, 6.x versions prior to 6.2.4
  • Apache ActiveMQ All module 5.x versions prior to 5.19.2, 6.x versions prior to 6.2.4
  • Apache ActiveMQ MQTT module 5.x versions prior to 5.19.2, 6.x versions prior to 6.2.4

Description

Apache ActiveMQ series provided by The Apache Software Foundation does not properly validate the remaining length field of MQTT packets, which may lead to integer overflow and misinterpretation of MQTT packets.

  • Integer overflow or wraparound (CWE-190)
    • CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N Base Score 5.3
    • CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N Base Score 5.4
    • CVE-2025-66168, CVE-2026-40046

Impact

Processing a crafted MQTT packet may lead to misinterpretation of the packet and unexpected behavior.

Solution

Update the Software
Update the software to the latest version according to the information provided by the developer.

References

JPCERT/CC Addendum

Vulnerability Analysis by JPCERT/CC

Credit

Gai Tanaka of Mitsui Bussan Secure Directions, Inc. reported this vulnerability in version 6.2.0 to the developer and IPA under Information Security Early Warning Partnership.
JPCERT/CC coordinated with the developer to publish the advisory.

Other Information

JPCERT Alert
JPCERT Reports
CERT Advisory
CPNI Advisory
TRnotes
CVE
JVN iPedia JVNDB-2026-006408