CVE-2026-40466 Apache ActiveMQ Vulnerable to Improper Input Validation and Code Injection

What is CVE-2026-40466?

CVE-2026-40466 is a high-severity code injection vulnerability in Apache Activemq, published on 24 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

Improper Input Validation, Improper Control of Generation of Code ('Code Injection') vulnerability in Apache ActiveMQ Broker, Apache ActiveMQ All, Apache ActiveMQ.

An authenticated attacker may bypass the fix in CVE-2026-34197 by adding a connector using an HTTP Discovery transport via BrokerView.addNetworkConnector or BrokerView.addConnector through Jolokia if the activemq-http module is on the classpath. A malicious HTTP endpoint can return a VM transport through the HTTP URI which will bypass the validation added in CVE-2026-34197. The attacker can then use the VM transport's brokerConfig parameter to load a remote Spring XML application context using ResourceXmlApplicationContext. Because Spring's ResourceXmlApplicationContext instantiates all singleton beans before the BrokerService validates the configuration, arbitrary code execution occurs on the broker's JVM through bean factory methods such as Runtime.exec().

This issue affects Apache ActiveMQ Broker: before 5.19.6, from 6.0.0 before 6.2.5; Apache ActiveMQ All: before 5.19.6, from 6.0.0 before 6.2.5; Apache ActiveMQ: before 5.19.6, from 6.0.0 before 6.2.5.

Users are recommended to upgrade to version 5.19.6 or 6.2.5, which fixes the issue.

Weakness: CWE-94, CWE-20

Which versions are affected by CVE-2026-40466?

13 open source packages ship an affected version, including org.apache.activemq:activemq-all, activemq and org.apache.activemq:activemq-broker. It affects 2 products.

Products include Apache Activemq, Apache Activemq Broker.

How do I fix CVE-2026-40466?

Upgrade org.apache.activemq:activemq-all to a fixed version for your release line: 5.19.6 or 6.2.5.

Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.

Is CVE-2026-40466 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-40466 exists.

Public exploit code: 1 Nuclei template.

Other vulnerabilities in Apache Activemq

• CVE-2023-46604 Apache ActiveMQ Deserialization of Untrusted Data Exploited Critical 10.0
• CVE-2016-3088 Apache ActiveMQ Improper Input Validation Exploited Critical 9.8
• CVE-2026-34197 Apache ActiveMQ Improper Input Validation Exploited High 8.8
• CVE-2020-11998 Remote code execution in Apache ActiveMQ Critical 9.8
• CVE-2013-7285 Command Injection in Xstream Critical 9.8

All Apache Activemq vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as BIT-activemq-2026-40466, DEBIAN-CVE-2026-40466, GHSA-w3w2-mpp5-92gm, MINI-5q94-4cm7-4j2v, MINI-cqqg-h2pg-fjf6, MINI-frhq-vww8-c28v and 3 more.