Executive brief
Apache ActiveMQ, a popular open-source message broker used for communication between different software applications, is vulnerable to a denial-of-service attack. An unauthenticated attacker can repeatedly send specific commands that exhaust the server's memory, causing the broker to crash. This results in a complete service outage, preventing applications from exchanging messages and potentially disrupting business operations.
Technical details
A Denial of Service (DoS) vulnerability exists in Apache ActiveMQ due to improper resource management when handling BrokerInfo commands. An unauthenticated remote attacker can exploit this by repeatedly sending BrokerInfo commands without initiating a ConnectionInfo sequence. This behavior leads to an Out of Memory (OOM) condition, causing the broker process to crash. This issue emerged as a regression following the fix for CVE-2026-49270. The vulnerability is addressed in version 6.2.7.
Affected products
- Apache ActiveMQ Broker 5.19.7 to 5.19.8, 6.2.6 to 6.2.7
- Apache ActiveMQ 5.19.7 to 5.19.8, 6.2.6 to 6.2.7
- Apache ActiveMQ All 5.19.7 to 5.19.8, 6.2.6 to 6.2.7
Timeline
- 2026-06-30: disclosed
- 2026-06-30: advisory