CVE-2026-53917: Apache ActiveMQ

High severity, CVSS 7.5. EPSS: 0.7% chance of exploitation in the next 30 days.

Memory Allocation with Excessive Size Value vulnerability in Apache ActiveMQ, Apache ActiveMQ All, Apache ActiveMQ Client, Apache ActiveMQ Broker. An authenticated user can cause a broker DoS by sending a crafted OpenWire Message with a large encoded size value for the map. OpenWire message property maps are unmarshaled without size validation which can trigger OOM and crash the broker. This issue affects Apache ActiveMQ: before 5.19.8, from 6.0.0 before 6.2.7; Apache ActiveMQ All: before 5.19.8, from 6.0.0 before 6.2.7; Apache ActiveMQ Client: before 5.19.8, from 6.0.0 before 6.2.7; Apache ActiveMQ Broker: before 5.19.8, from 6.0.0 before 6.2.7. Users are recommended to upgrade to version 6.2.7 or 5.19.8, which fixes the issue.

Affected products

• Apache ActiveMQ: before 5.19.8 (fixed in 5.19.8); from 6.0.0, before 6.2.7 (fixed in 6.2.7)
• Apache ActiveMQ Broker: before 5.19.8 (fixed in 5.19.8); from 6.0.0, before 6.2.7 (fixed in 6.2.7)

Published 2026-06-30. Last modified 2026-07-02.