XXE in IBM Mq

CVE-2026-12667

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 read files from a vulnerable .NET client or cause limited denial of service due to improper handling of XML external entities in RFH2 folder parsing.

Vulnerability class: XXE (XML External Entity)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:L.

EPSS exploit prediction

EPSS: 0.003 (18.5th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 18th percentile — 18.5% 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-2026-12667: held from 0.003 to 0.003.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-12667?
CVE-2026-12667 is a high-severity vulnerability in IBM Mq, classified under Improper Restriction of XML External Entity Reference (XXE). CVSS score: 7.1/10. Published 2026-09-15.
How severe is CVE-2026-12667?
High severity. CVSS v3 base score is 7.1 out of 10.