CVE-2026-33227

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.

Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files. Typical impact: unauthorized file read or write outside the intended directory.

CVE-2026-33227 has a CVSS score of 4.3 (Medium). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (5.19.3, 6.2.2); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2026-33227? CVE-2026-33227 is a medium-severity path traversal vulnerability in org.apache.activemq:activemq-client (maven), affecting versions < 5.19.3. It is fixed in 5.19.3, 6.2.2. Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files.
2. How severe is CVE-2026-33227? CVE-2026-33227 has a CVSS score of 4.3 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which packages are affected by CVE-2026-33227?
   • org.apache.activemq:activemq-client (maven) (versions < 5.19.3)
   • org.apache.activemq:activemq-broker (maven) (versions < 5.19.3)
   • org.apache.activemq:activemq-all (maven) (versions < 5.19.3)
   • org.apache.activemq:activemq-web (maven) (versions < 5.19.3)
4. Is there a fix for CVE-2026-33227? Yes. CVE-2026-33227 is fixed in 5.19.3, 6.2.2. Upgrade to this version or later.
5. Is CVE-2026-33227 exploitable, and should I be worried? Whether CVE-2026-33227 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-33227 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-33227?
   • Upgrade org.apache.activemq:activemq-client to 5.19.3 or later
   • Upgrade org.apache.activemq:activemq-client to 6.2.2 or later
   • Upgrade org.apache.activemq:activemq-broker to 5.19.3 or later
   • Upgrade org.apache.activemq:activemq-broker to 6.2.2 or later
   • Upgrade org.apache.activemq:activemq-all to 5.19.3 or later
   • Upgrade org.apache.activemq:activemq-all to 6.2.2 or later
   • Upgrade org.apache.activemq:activemq-web to 5.19.3 or later
   • Upgrade org.apache.activemq:activemq-web to 6.2.2 or later