Apache ActiveMQ users need to act swiftly by updating their systems following the disclosure of three critical vulnerabilities. These flaws put messaging infrastructures at risk of denial-of-service (DoS) attacks, broken isolation, and improper authorization.
Critical Vulnerabilities Identified
The identified vulnerabilities, labeled CVE-2026-53917, CVE-2026-54475, and CVE-2026-49877, affect core components of both the 5.x and 6.x versions. If unaddressed, these flaws could lead to broker crashes and unauthorized access.
CVE-2026-53917 involves a “Memory Allocation with Excessive Size Value” issue. This vulnerability resides in how OpenWire message property maps are processed. A crafted message sent by an authenticated user can cause the broker to allocate excessive memory, leading to out-of-memory (OOM) conditions and potential DoS attacks.
Impact on OpenWire Clients
Environments using OpenWire clients are particularly vulnerable as a single compromised client could incapacitate the broker. Affected versions include Apache ActiveMQ before 5.19.8 and from 6.0.0 before 6.2.7.
CVE-2026-54475, a “Missing Authorization” flaw, affects the Apache ActiveMQ Broker, among others. In ActiveMQ Classic, temporary destinations should be isolated to their creating connection. However, the broker fails to enforce this, allowing unauthorized access to message flows.
Web Console Authorization Vulnerability
CVE-2026-49877 is an “Improper Authorization” issue within the Apache ActiveMQ Web Console. Due to insecure Jetty configurations, low-privilege users could access admin paths, gaining elevated permissions inadvertently.
This affects all Apache ActiveMQ versions before 5.19.8 and from 6.0.0 to 6.2.7. Users are advised to upgrade to versions 6.2.7 or 5.19.8, which introduce necessary security measures.
Recommended Actions for Users
Apache advises immediate updates to mitigate these vulnerabilities. The updates enforce size validation, proper authorization checks, and restrict administrative access to authorized users only.
Organizations should also restrict network access, review roles and permissions, and monitor for abnormal system behaviors. Keeping systems updated ensures the integrity and security of messaging infrastructures.
Through these measures, users can safeguard their systems from potential threats and maintain secure communication channels.
