Quick answers
- Is CVE-2026-12356 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-12356 being exploited in the wild.
- How severe is CVE-2026-12356?
- High severity, with a CVSS score of 7.5, published 4 November 2026.
- Which products and versions are affected?
- IBM Mq 10.0.0.0 through 10.0.0.5 LTS and CD.
- Is there a fix for CVE-2026-12356?
- 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-2026-12356 attacked?
- It is attacked over the network, in a hosted service.
- Am I affected by CVE-2026-12356?
- 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 is an improper neutralization of special elements in output used by a downstream component (CWE-74), affecting Ant script command execution. An authenticated attacker with command queue access can inject malicious arguments to achieve arbitrary code execution. The attack requires authentication and network access, and no user interaction is needed once the attacker has queue access.
Affected products
- IBM MQ 9.2.0.0 through 9.2.0.44 LTS
- IBM MQ 9.3.0.0 through 9.3.0.42 LTS
- IBM MQ 9.4.0.0 through 9.4.0.26 LTS
- IBM MQ 9.4.0.0 through 9.4.5.1 CD
- IBM MQ 10.0.0.0 through 10.0.0.5 LTS and CD
Timeline
- 2026-10-29: disclosed