# CVE-2026-18142: IBM MQ integer overflow in malformed MQINQ request

Source: https://junglewise.ai/threats/cve-2026-18142-ibm-mq-9-2-0-0-through-9-2-0-44-lts-9-3-0-0-through-9-3-0-42-lts  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-04. Updated: 2026-11-04  
License: CC BY 4.0 with a link back

CVE-2026-18142 · Severity: high · CVSS 7.1 · Published 2026-11-04

IBM MQ is a message queue server that enables enterprise applications to communicate asynchronously. An authenticated remote attacker can exploit an integer overflow vulnerability by sending a malformed MQINQ request, causing the service to crash (denial of service) or potentially corrupting memory. This could disrupt critical messaging infrastructure or enable follow-on attacks.

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

## Quick answers

**Is CVE-2026-18142 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-18142 being exploited in the wild.

**How severe is CVE-2026-18142?** High severity, with a CVSS score of 7.1, published 4 November 2026.

**Which products and versions are affected?** IBM Mq 9.2.0.0–9.2.0.44 LTS, 9.3.0.0–9.3.0.42 LTS, 9.4.0.0–9.4.0.26 LTS, 9.4.0.0–9.4.5.1 CD, 10.0.0.0–10.0.0.5 LTS and CD.

**Is there a fix for CVE-2026-18142?** Yes: fixed in IBM MQ 9.2.0.46, 9.3.0.43, 9.4.0.30, 10.0.0.6, 10.0.1.0. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-18142 attacked?** It is attacked over the network, in a hosted service.

**Am I affected by CVE-2026-18142?** 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, 9.3.0.43, 9.4.0.30, 10.0.0.6, 10.0.1.0

## Technical details

An integer overflow (CWE-190) in IBM MQ's MQINQ request handler allows a remote authenticated attacker to trigger a denial of service or limited memory corruption. The vulnerability requires network access and prior authentication. Exploitation occurs via a specially crafted malformed MQINQ request that triggers the integer overflow condition.

## Affected products

- IBM MQ 9.2.0.0–9.2.0.44 LTS, 9.3.0.0–9.3.0.42 LTS, 9.4.0.0–9.4.0.26 LTS, 9.4.0.0–9.4.5.1 CD, 10.0.0.0–10.0.0.5 LTS and CD

## Timeline

- 2026-10-29: disclosed

## References

- [https://www.ibm.com/support/pages/node/7294663](https://www.ibm.com/support/pages/node/7294663)

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