Buffer overflow in IBM Mq

CVE-2026-12550

IBM MQ 9.2.0.0 through 9.2.0.44 LTS, 9.3.0.0 through 9.3.0.42 LTS, 9.4.0.0 through 9.4.0.26 LTS, 9.4.0.0 through 9.4.5.1 CD, and 10.0.0.0 through 10.0.0.5 LTS and CD could allow an authenticated attacker to obtain sensitive information or cause a denial of service due to improper validation of message selection parameters.

Vulnerability class: Buffer Overflow

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

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-12550?
CVE-2026-12550 is a medium-severity vulnerability in IBM Mq, classified under Heap-based Buffer Overflow. CVSS score: 5.4/10. Published 2026-11-04.
How severe is CVE-2026-12550?
Medium severity. CVSS v3 base score is 5.4 out of 10.