CVE-2026-33227: Apache ActiveMQ Client, Apache ActiveMQ Broker, Apache ActiveMQ, Apache ActiveMQ Web: Improper Limitation of a Pathname to a Restricted Directory

["Christopher L. Shannon" <cshannon () apache org>]

Severity: low 

Affected versions:

- Apache ActiveMQ Client (org.apache.activemq:activemq-client) before 5.19.3
- Apache ActiveMQ Client (org.apache.activemq:activemq-client) 6.0.0 before 6.2.2
- Apache ActiveMQ Broker (org.apache.activemq:activemq-broker) before 5.19.3
- Apache ActiveMQ Broker (org.apache.activemq:activemq-broker) 6.0.0 before 6.2.2
- Apache ActiveMQ (org.apache.activemq:activemq-all) before 5.19.3
- Apache ActiveMQ (org.apache.activemq:activemq-all) 6.0.0 before 6.2.2
- Apache ActiveMQ Web (org.apache.activemq:activemq-web) before 5.19.3
- Apache ActiveMQ Web (org.apache.activemq:activemq-web) 6.0.0 before 6.2.2

Description:

Improper validation and restriction of a classpath path name vulnerability in Apache ActiveMQ Client, Apache ActiveMQ 
Broker, Apache ActiveMQ All.

In two instances (when creating a Stomp consumer and also browsing messages in the Web console) an authenticated user 
provided "key" value could be constructed to traverse the classpath due to path concatenation. As a result, the 
application is exposed to a classpath path resource loading vulnerability that could potentially be chained together 
with another attack to lead to exploit.This issue affects Apache ActiveMQ Client: before 5.19.3, from 6.0.0 before 
6.2.2; Apache ActiveMQ Broker: before 5.19.3, from 6.0.0 before 6.2.2; Apache ActiveMQ All: before 5.19.3, from 6.0.0 
before 6.2.2.

Users are recommended to upgrade to version 5.19.4 or 6.2.3, which fixes the issue. Note: 5.19.3 and 6.2.2 also fix 
this issue, but that is limited to non-Windows environments due to a path separator resolution bug fixed in 5.19.4 and 
6.2.3.

Credit:

Dawei Wang (finder)

References:

https://activemq.apache.org/
https://www.cve.org/CVERecord?id=CVE-2026-33227