CVE-2026-33227: Apache ActiveMQ: Improper validation and restriction of a classpath path name

CVE-2026-33227 · Severity: medium · CVSS 4.3 · Published 2026-04-07

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.

Technologies: Apache ActiveMQ, Apache Activemq Broker, org.apache.activemq:activemq-all (Maven), org.apache.activemq:activemq-broker (Maven), org.apache.activemq:activemq-client (Maven). Vendors: Apache, Maven.

Quick answers

Is CVE-2026-33227 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-33227 being exploited in the wild.
How severe is CVE-2026-33227?
Medium severity, with a CVSS score of 4.3, published 7 April 2026.
Which products and versions are affected?
org.apache.activemq:activemq-all (Maven) ECOSYSTEM:introduced=0,fixed=5.19.3; org.apache.activemq:activemq-broker (Maven) ECOSYSTEM:introduced=0,fixed=5.19.3; org.apache.activemq:activemq-client (Maven) ECOSYSTEM:introduced=0,fixed=5.19.3; org.apache.activemq:activemq-web (Maven) ECOSYSTEM:introduced=0,fixed=5.19.3.
Is there a fix for CVE-2026-33227?
Yes. org.apache.activemq:activemq-all (Maven): upgrade to 5.19.3 or later; org.apache.activemq:activemq-broker (Maven): upgrade to 5.19.3 or later; org.apache.activemq:activemq-client (Maven): upgrade to 5.19.3 or later; org.apache.activemq:activemq-web (Maven): upgrade to 5.19.3 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
Am I affected by CVE-2026-33227?
Check whether you run Apache ActiveMQ, Apache Activemq Broker, Apache Activemq Web or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • org.apache.activemq:activemq-all (Maven): upgrade to 5.19.3 or later
    # set org.apache.activemq:activemq-all to 5.19.3 in your pom.xml or build.gradle
  • org.apache.activemq:activemq-broker (Maven): upgrade to 5.19.3 or later
    # set org.apache.activemq:activemq-broker to 5.19.3 in your pom.xml or build.gradle
  • org.apache.activemq:activemq-client (Maven): upgrade to 5.19.3 or later
    # set org.apache.activemq:activemq-client to 5.19.3 in your pom.xml or build.gradle
  • org.apache.activemq:activemq-web (Maven): upgrade to 5.19.3 or later
    # set org.apache.activemq:activemq-web to 5.19.3 in your pom.xml or build.gradle

Affected products

  • Apache ActiveMQ
  • Apache Activemq Broker
  • Apache Activemq Web
  • org.apache.activemq:activemq-all (Maven) ECOSYSTEM:introduced=0,fixed=5.19.3
  • org.apache.activemq:activemq-broker (Maven) ECOSYSTEM:introduced=0,fixed=5.19.3
  • org.apache.activemq:activemq-client (Maven) ECOSYSTEM:introduced=0,fixed=5.19.3
  • org.apache.activemq:activemq-web (Maven) ECOSYSTEM:introduced=0,fixed=5.19.3

Identifiers

  • CVE-2026-33227
  • GHSA-h2h4-5m64-m273

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