CVE-2026-10859: IBM MQ arbitrary code execution in ObjectMessage deserialization

CVE-2026-10859 · Severity: high · CVSS 7.5 · Published 2026-11-04

IBM MQ is a message queuing system used to integrate applications across enterprise networks. An authenticated attacker can exploit insecure deserialization of ObjectMessage payloads in the .NET messaging component to execute arbitrary code on consumer applications. This could allow an attacker with valid credentials to compromise any application consuming messages from an affected MQ system.

Technologies: IBM Mq. Vendors: IBM.

Quick answers

Is CVE-2026-10859 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-10859 being exploited in the wild.
How severe is CVE-2026-10859?
High severity, with a CVSS score of 7.5, published 4 November 2026.
Which products and versions are affected?
IBM Mq 9.2.0.0 through 9.2.0.44 LTS, 9.3.0.0 through 9.3.0.42 LTS, 9.4.0.0 through 9.4.0.26 LTS, 9.4.0.0 through 9.4.5.1 CD, 10.0.0.0 through 10.0.0.5 LTS and CD.
Is there a fix for CVE-2026-10859?
Yes: fixed in IBM MQ 9.2.0.46 LTS, 9.3.0.43 LTS, 9.4.0.30 LTS, 10.0.0.6 LTS, 10.0.1.0 CD. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-10859 attacked?
It is attacked over the network, in a hosted service.
Am I affected by CVE-2026-10859?
Check whether you run IBM Mq at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • Fixed in: IBM MQ 9.2.0.46 LTS, 9.3.0.43 LTS, 9.4.0.30 LTS, 10.0.0.6 LTS, 10.0.1.0 CD

Technical details

The vulnerability exists in IBM MQ's .NET client library due to unsafe deserialization of ObjectMessage payloads. An authenticated attacker sending specially crafted messages can trigger arbitrary code execution on consumer applications that process those messages. This requires prior authentication to the MQ system and affects multiple LTS and CD release lines.

Affected products

  • IBM MQ 9.2.0.0 through 9.2.0.44 LTS, 9.3.0.0 through 9.3.0.42 LTS, 9.4.0.0 through 9.4.0.26 LTS, 9.4.0.0 through 9.4.5.1 CD, 10.0.0.0 through 10.0.0.5 LTS and CD

Timeline

  • 2026-10-29: disclosed

References

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