CVE-2026-33227
Apache ActiveMQ: Improper validation and restriction of a classpath path name
Description
Improper validation and restriction of a classpath path name vulnerability in Apache ActiveMQ Client, Apache ActiveMQ Broker, Apache ActiveMQ All, Apache ActiveMQ Web, Apache ActiveMQ. 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; Apache ActiveMQ Web: before 5.19.3, from 6.0.0 before 6.2.2; Apache ActiveMQ: 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.
How to fix CVE-2026-33227
To remediate CVE-2026-33227, upgrade the affected package to a fixed version below.
- —upgrade to 5.19.3 or later
- —no fix listed
- —upgrade to 5.19.3 or later
- —upgrade to 5.19.3 or later
- —upgrade to 5.19.3 or later
- —upgrade to 5.19.3 or later
Is CVE-2026-33227 being exploited?
Low — EPSS is 0.1%, meaning exploitation activity has not been observed at scale.