Deserialization in IBM Mq

CVE-2026-12728

IBM MQ 9.1.0.0 through 9.1.0.37 LTS, 9.2.0.0 through 9.2.0.43 LTS, 9.3.0.0 through 9.3.0.41 LTS, 9.3.0.0 through 9.3.5.1 CD, 9.4.0.0 through 9.4.0.25 LTS, 9.4.0.0 through 9.4.5.1 CD, and 10.0.0.0 could allow an authenticated attacker to execute arbitrary code due to a deserialization of untrusted data.

Vulnerability class: Insecure Deserialization

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.007 (52.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 53rd percentile — 52.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-12728: held from 0.004 to 0.007.

EPSS over last 30 days · oldest: 0.004 · newest: 0.007 · change: +0.003

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-12728?
CVE-2026-12728 is a high-severity vulnerability in IBM Mq, classified under Deserialization of Untrusted Data. CVSS score: 8.8/10. Published 2026-09-15.
How severe is CVE-2026-12728?
High severity. CVSS v3 base score is 8.8 out of 10.