Severity: important

Affected versions:

- Apache ActiveMQ (org.apache.activemq:apache-activemq) before 5.19.8
- Apache ActiveMQ (org.apache.activemq:apache-activemq) 6.0.0 before 6.2.7
- Apache ActiveMQ All (org.apache.activemq:activemq-all) before 5.19.8
- Apache ActiveMQ All (org.apache.activemq:activemq-all) 6.0.0 before 6.2.7
- Apache ActiveMQ Client (org.apache.activemq:activemq-client) before 5.19.8
- Apache ActiveMQ Client (org.apache.activemq:activemq-client) 6.0.0 before 6.2.7
- Apache ActiveMQ Broker (org.apache.activemq:activemq-broker) before 5.19.8
- Apache ActiveMQ Broker (org.apache.activemq:activemq-broker) 6.0.0 before 6.2.7

Description:

Memory Allocation with Excessive Size Value vulnerability in Apache ActiveMQ, Apache ActiveMQ All, Apache ActiveMQ Client, Apache ActiveMQ Broker.

An authenticated user can cause a broker DoS by sending a crafted OpenWire Message with a large encoded size value for the map. OpenWire message property maps are unmarshaled without size validation which can trigger OOM and crash the broker.
This issue affects Apache ActiveMQ: before 5.19.8, from 6.0.0 before 6.2.7; Apache ActiveMQ All: before 5.19.8, from 6.0.0 before 6.2.7; Apache ActiveMQ Client: before 5.19.8, from 6.0.0 before 6.2.7; Apache ActiveMQ Broker: before 5.19.8, from 6.0.0 before 6.2.7.

Users are recommended to upgrade to version 6.2.7 or 5.19.8, which fixes the issue.

Credit:

tonghuaroot (finder)

References:

https://activemq.apache.org/
https://www.cve.org/CVERecord?id=CVE-2026-53917