CVE-2026-12666 IBM MQ - XML External Entity Injection

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 Classes for Java contain an XML external entity injection caused by improper MQRFH2 header processing, letting authenticated attackers obtain sensitive information or cause denial of service, exploit requires authentication.

CVSS base score 8.1 /10
High
CISA KEV
Not listed
Public exploit
None known
Authentication
Required
EPSS
0.26% chance of exploitation in 30 days
View the NVD record ↗

Details

Type
XML External Entity Injection
Impact
Information Disclosure, Denial Of Service
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
Published
15 September 2026
Updated
15 October 2026
Weakness
CWE-611

Vendor fix

Update to the latest available version beyond 10.0.0.0 or apply vendor patches.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

References

← All CVEs