Vulnerability in IBM Mq Appliance

CVE-2026-12538

IBM MQ 9.4.0.0 to 9.4.0.26, 9.4.1.0 to 9.4.5.3, and 10.0.0.1 to 10.0.0.5 could allow an authenticated attacker to obtain sensitive information or cause a denial of service due to improper validation of message header structure length fields.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:L.

EPSS exploit prediction

EPSS: 0.003 (26.7th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 27th percentile — 26.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

The 30-day trend appears once there are two daily scores.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-12538?
CVE-2026-12538 is a medium-severity vulnerability in IBM Mq Appliance, classified under Buffer Underwrite. CVSS score: 5.4/10. Published 2026-11-04.
How severe is CVE-2026-12538?
Medium severity. CVSS v3 base score is 5.4 out of 10.