HIGH

CVE-2026-12666

CVSS v3

8.1

HIGH

EPSS Score

0.3 %

exploit probability, as of 2026-09-28

CISA KEV

known exploited

Exploitation

—

SSVC status

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.

Technical details

Published: 2026-09-15
Last Modified: 2026-09-16

Frequently asked questions

What is CVE-2026-12666?

Is CVE-2026-12666 actively exploited?

Active exploitation of CVE-2026-12666 has not been confirmed. Its EPSS score was 0.3% on 2026-09-28, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-12666?

CVE-2026-12666 has a CVSS v3 base score of 8.1 (HIGH severity).

Is CVE-2026-12666 affecting your environment?

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