CVE-2026-12666

IBM MQ Java messaging is vulnerable to XML external entity injection

Published Sep 15, 2026 CVSS 3.1 · 8.1 High EPSS < 1% KEV · Not listed

Description

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 could allow an authenticated attacker to obtain sensitive information or cause a denial of service due to XML external entity injection in MQRFH2 header processing.

Affected Products

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

IBM

affected

Version	Status	Constraints
`9.1.0.0`	affected	≤ 9.1.0.37 LTS
`9.2.0.0`	affected	≤ 9.2.0.43 LTS
`9.3.0.0`	affected	≤ 9.3.0.41 LTS
`9.3.0.0`	affected	≤ 9.3.5.1 CD
`9.4.0.0`	affected	≤ 9.4.0.25 LTS
`9.4.0.0`	affected	≤ 9.4.5.1 CD
`10.0.0.0`	affected	—

No data.

Vendor Product Versions

Ibm

Version	Status	Scheme	Platform
`[9.1.0.0,9.1.0.37 LTS]`	affected	generic	—
`[9.2.0.0,9.2.0.43 LTS]`	affected	generic	—
`[9.3.0.0,9.3.0.41 LTS]`	affected	generic	—
`[9.3.0.0,9.3.5.1 CD]`	affected	generic	—
`[9.4.0.0,9.4.0.25 LTS]`	affected	generic	—
`[9.4.0.0,9.4.5.1 CD]`	affected	generic	—
`10.0.0.0`	affected	generic	—

Remediation

Vendor Solution

This issue was addressed under Known Issue DT474364 IBM MQ version 9.1 LTS Apply cumulative security update 9.1.0.38 https://www.ibm.com/support/pages/downloading-ibm-mq-91-lts IBM MQ version 9.2 LTS Apply cumulative security update 9.2.0.44 https://www.ibm.com/support/pages/downloading-ibm-mq-92-lts IBM MQ version 9.3 LTS Apply cumulative security update 9.3.0.42 https://www.ibm.com/support/pages/downloading-ibm-mq-93-lts IBM MQ version 9.4 LTS Apply cumulative security update https://www.ibm.com/support/pages/downloading-ibm-mq-94-lts 9.4.0.26 https://www.ibm.com/support/pages/downloading-ibm-mq-94-lts IBM MQ version 9.3 CD, 9.4 CD and 10.0.0.0 Upgrade to IBM MQ version 10.0.0.5 https://www.ibm.com/support/pages/downloading-ibm-mq-100

Tracking

Advisories

No advisories available

Metrics

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact High

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploit prediction score: < 1% (0.462% probability within 30 days)

Exploitation none

Automatable no

Technical Impact partial

References

Link	Providers
https://www.ibm.com/support/pages/node/7284939

History

Sep 17, 2026 5:30 PM Scoring metrics updated View changes

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}`

Sep 15, 2026 5:30 PM Description updated. Title updated. First appearance in the feed. Weaknesses updated. Affected versions updated. Affected vendors updated. Added references. Scoring metrics updated View changes

Type	Values Removed	Values Added
Description		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 could allow an authenticated attacker to obtain sensitive information or cause a denial of service due to XML external entity injection in MQRFH2 header processing.
Title		IBM MQ Java messaging is vulnerable to XML external entity injection
First Time appeared		Ibm Ibm mq
Weaknesses		CWE-611
CPEs		cpe:2.3:a:ibm:mq:10.0.0.0:::::::* cpe:2.3:a:ibm:mq:9.1.0.0:::::::* cpe:2.3:a:ibm:mq:9.1.0.37:::::::* cpe:2.3:a:ibm:mq:9.2.0.0:::::::* cpe:2.3:a:ibm:mq:9.2.0.43:::::::* cpe:2.3:a:ibm:mq:9.3.0.0:::::::* cpe:2.3:a:ibm:mq:9.3.0.41:::::::* cpe:2.3:a:ibm:mq:9.3.5.1:::::::* cpe:2.3:a:ibm:mq:9.4.0.0:::::::* cpe:2.3:a:ibm:mq:9.4.0.25:::::::* cpe:2.3:a:ibm:mq:9.4.5.1:::::::*
Vendors & Products		Ibm Ibm mq
References		https://www.ibm.com/support/pages/node/7284939
Metrics		cvssV3_1 `{'score': 8.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H'}`