Quick answers
- Is CVE-2026-12550 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-12550 being exploited in the wild.
- How severe is CVE-2026-12550?
- Medium severity, with a CVSS score of 5.4, 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-2026-12550?
- Yes: fixed in 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-2026-12550 attacked?
- It is attacked over the network.
- Am I affected by CVE-2026-12550?
- 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: 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
A heap-based buffer overflow exists in IBM MQ's message selection parameter validation (CWE-122). The vulnerability requires prior authentication and network access to the MQ server. An attacker can trigger the overflow to leak memory contents or trigger a denial of service; fixes are available in the versions listed below.
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