# CVE-2026-12728: IBM MQ deserialization bypass remote code execution

Source: https://junglewise.ai/threats/cve-2026-12728-ibm-mq-deserialization-bypass-remote-code-execution  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-15. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-12728 · Severity: high · CVSS 8.8 · Published 2026-09-15

IBM MQ is a message queuing system used to reliably transmit messages between applications in enterprise environments. A flaw in the Java client's deserialization handling allows authenticated attackers to bypass security filters and execute arbitrary code by sending specially crafted messages, potentially compromising the entire messaging infrastructure and any connected systems.

Technologies: [IBM Mq](https://junglewise.ai/threats/technologies/mq). Vendors: [IBM](https://junglewise.ai/threats/vendors/ibm).

## Quick answers

**Is CVE-2026-12728 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-12728 being exploited in the wild.

**How severe is CVE-2026-12728?** High severity, with a CVSS score of 8.8, published 15 September 2026.

**Which products and versions are affected?** IBM Mq 9.1.0.0 to 9.1.0.37 LTS, 9.2.0.0 to 9.2.0.43 LTS, 9.3.0.0 to 9.3.0.41 LTS, 9.3.0.0 to 9.3.5.1 CD, 9.4.0.0 to 9.4.0.25 LTS, 9.4.0.0 to 9.4.5.1 CD, 10.0.0.0.

**Is there a fix for CVE-2026-12728?** A patch was published on 2026-09-14: Patches available: MQ 9.1.0.38, 9.2.0.44, 9.3.0.42, 9.4.0.26 LTS, and 10.0.0.5 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-12728 attacked?** It is attacked over the network, in a hosted service.

**Am I affected by CVE-2026-12728?** 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.

## Technical details

This is a deserialization filter bypass vulnerability in IBM MQ's Java messaging component. The vulnerability exists in the distributed messaging component where the deserialization allowlist can be bypassed by an authenticated attacker sending crafted serialized messages. The attack requires network access to the MQ infrastructure and valid authentication credentials. Successful exploitation allows remote code execution with the privileges of the MQ process. IBM has released patches for all affected versions, with versions 9.1 through 9.4 LTS requiring cumulative security updates and 10.0.0.0 requiring an upgrade to 10.0.0.5.

## Affected products

- IBM MQ 9.1.0.0 to 9.1.0.37 LTS, 9.2.0.0 to 9.2.0.43 LTS, 9.3.0.0 to 9.3.0.41 LTS, 9.3.0.0 to 9.3.5.1 CD, 9.4.0.0 to 9.4.0.25 LTS, 9.4.0.0 to 9.4.5.1 CD, 10.0.0.0

## Timeline

- 2026-09-14: disclosed: IBM security bulletin published
- 2026-09-14: patched: Patches available: MQ 9.1.0.38, 9.2.0.44, 9.3.0.42, 9.4.0.26 LTS, and 10.0.0.5

## References

- [https://www.ibm.com/support/pages/node/7284942](https://www.ibm.com/support/pages/node/7284942)

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