CVE-2026-33227
MEDIUMCVE-2026-33227 is a medium-severity (CVSS 4.3) Path Traversal vulnerability in org.apache.activemq:activemq-client. O3 Security confirms whether CVE-2026-33227 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Apache ActiveMQ Client, Apache ActiveMQ Broker, Apache ActiveMQ All, Apache ActiveMQ Web, Apache ActiveMQ: Improper Limitation of a Pathname to a Restricted Classpath Directory
Real-World Exposure
org.apache.activemq:activemq-client☕org.apache.activemq:activemq-client☕org.apache.activemq:activemq-broker☕org.apache.activemq:activemq-broker☕org.apache.activemq:activemq-all☕org.apache.activemq:activemq-all☕org.apache.activemq:activemq-web☕org.apache.activemq:activemq-webReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.apache.activemq:activemq-client | all versions | 5.19.3 |
| ☕Maven | org.apache.activemq:activemq-client | ≥ 6.0.0&&< 6.2.2 | 6.2.2 |
| ☕Maven | org.apache.activemq:activemq-broker | all versions | 5.19.3 |
| ☕Maven | org.apache.activemq:activemq-broker | ≥ 6.0.0&&< 6.2.2 | 6.2.2 |
| ☕Maven | org.apache.activemq:activemq-all | all versions | 5.19.3 |
| ☕Maven | org.apache.activemq:activemq-all | ≥ 6.0.0&&< 6.2.2 | 6.2.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.activemq:activemq-client. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update org.apache.activemq:activemq-client to 5.19.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-33227 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-33227 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-33227. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-33227 in your dependencies?
O3 detects CVE-2026-33227 across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.