CVE-2025-54539

A Deserialization of Untrusted Data vulnerability exists in the Apache ActiveMQ NMS AMQP Client.

This issue affects all versions of Apache ActiveMQ NMS AMQP up to and including 2.3.0, when establishing connections to untrusted AMQP servers. Malicious servers could exploit unbounded deserialization logic present in the client to craft responses that may lead to arbitrary code execution on the client side.

Although version 2.1.0 introduced a mechanism to restrict deserialization via allow/deny lists, the protection was found to be bypassable under certain conditions.

In line with Microsoft’s deprecation of binary serialization in .NET 9, the project is evaluating the removal of .NET binary serialization support from the NMS API entirely in future releases.

Mitigation and Recommendations:
Users are strongly encouraged to upgrade to version 2.4.0 or later, which resolves the issue. Additionally, projects depending on NMS-AMQP should migrate away from .NET binary serialization as part of a long-term hardening strategy.

Untrusted serialized data is processed by a deserializer that can instantiate arbitrary objects or execute code as a side effect. Typical impact: arbitrary code execution or logic abuse.

CVE-2025-54539 has a CVSS score of 9.8 (Critical). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (2.4.0); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2025-54539? CVE-2025-54539 is a critical-severity insecure deserialization vulnerability in Apache.NMS.AMQP (nuget), affecting versions < 2.4.0. It is fixed in 2.4.0. Untrusted serialized data is processed by a deserializer that can instantiate arbitrary objects or execute code as a side effect.
2. How severe is CVE-2025-54539? CVE-2025-54539 has a CVSS score of 9.8 (Critical). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of Apache.NMS.AMQP are affected by CVE-2025-54539? Apache.NMS.AMQP (nuget) versions < 2.4.0 is affected.
4. Is there a fix for CVE-2025-54539? Yes. CVE-2025-54539 is fixed in 2.4.0. Upgrade to this version or later.
5. Is CVE-2025-54539 exploitable, and should I be worried? Whether CVE-2025-54539 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2025-54539 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2025-54539? Upgrade Apache.NMS.AMQP to 2.4.0 or later.