All vulnerabilities
CVE-2026-12343

MQ Operator: IBM MQ Denial of Service

IBM MQ Operator
CVSS
6.5Medium
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.24%Chance of exploitation activity in the next 30 days, higher than 13% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in3.4.0Fixed versionCVE List
Published19 Oct 2026Updated 19 Oct 2026CVE List

What fixes it

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

Description

IBM MQ could allow an authenticated attacker to cause a denial of service due to improper validation of RFH2 message header fields in queued publish/subscribe operations.

Text from CVE List

Affected versions 48

  • MQ Operatoraffected: 3.2.0 through 3.2.29CVE List
  • MQ Operatoraffected: 3.3.0 before 3.4.0CVE List
  • MQ Operatoraffected: 3.4.1CVE List
  • MQ Operatoraffected: 3.5.0CVE List
  • MQ Operatoraffected: 3.5.1 through 3.5.3CVE List
  • MQ Operatoraffected: 3.6.0 through 3.6.4CVE List
  • MQ Operatoraffected: 3.7.0 through 3.7.2CVE List
  • MQ Operatoraffected: 3.8.0CVE List
  • MQ Operatoraffected: 3.8.1CVE List
  • MQ Operatoraffected: 3.9.0CVE List
  • MQ Operatoraffected: 3.9.1CVE List
  • MQ Operatoraffected: 3.9.2CVE List
  • MQ Operatoraffected: 4.0.0CVE List
  • MQ Operatoraffected: 4.0.1CVE List
  • MQ Operatoraffected: 4.0.2CVE List
  • MQ Operatoraffected: 4.0.3CVE List
  • MQ Operatoraffected: 4.0.4CVE List
  • MQ Operatoraffected: 2.0.0 through 2.0.29CVE List
  • MQ Advanced container imagesaffected: 9.4.0.6-r1 through r1, 9.4.0.6-r2, 9.4.0.7-r1, 9.4.0.10-r1, 9.4.0.10-r2, 9.4.0.11-r1, 9.4.0.11-r2, 9.4.0.11-r3, 9.4.0.12-r1, 9.4.0.15-r1 - 9.4.0.15-r4, 9.4.0.16-r1, 9.4.0.16-r2, 9.4.0.17-r1, 9.4.0.17-r2, 9.4.0.20-r1, 9.4.0.21-r1, 9.4.0.21-r2, 9.4.0.25-r1 - 9.4.0.25-r3, 9.4.0.26-r1CD: 9.4.1.0-r1, 9.4.1.0-r2, 9.4.1.1-r1, 9.4.2.0-r1, 9.4.2.0-r2, 9.4.2.1-r1, 9.4.2.1-r2, 9.4.3.0-r1, 9.4.3.0-r2, 9.4.3.1-r1 - 9.4.3.1-r3, 9.4.4.0-r1 - 9.4.4.0-r4, 9.4.4.1-r1, 9.4.5.0-r1, 9.4.5.0-r2, 9.4.5.1-r1, 10.0.0.0-r1 - 10.0.0.0-r4, 10.0.0.5-r1LTS: 9.3.0.0-r1, 9.3.0.0-r2, 9.3.0.0-r3, 9.3.0.1-r1, 9.3.0.1-r2, 9.3.0.1-r3, 9.3.0.1-r4, 9.3.0.3-r1, 9.3.0.4-r1, 9.3.0.4-r2, 9.3.0.5-r1, 9.3.0.5-r2, 9.3.0.5-r3, 9.3.0.6-r1, 9.3.0.10-r1, 9.3.0.10-r2, 9.3.0.11-r1,9.3.0.11-r2, 9.3.0.15-r1, 9.3.0.16-r1, 9.3.0.16-r2, 9.3.0.17-r1, 9.3.0.17-r2, 9.3.0.17-r3, 9.3.0.20-r1, 9.3.0.20-r2, 9.3.0.21-r1, 9.3.0.21-r2, 9.3.0.21-r3, 9.3.0.25-r1, 9.4.0.0-r1, 9.4.0.0-r2, 9.4.0.0-r3, 9.4.0.5-r1, 9.4.0.5-r2CVE List
  • MQ Advanced container imagesaffected: 9.4.0.6-r2CVE List
  • MQ Advanced container imagesaffected: 9.4.0.7-r1CVE List
  • MQ Advanced container imagesaffected: 9.4.0.10-r1CVE List
  • MQ Advanced container imagesaffected: 9.4.0.10-r2CVE List
  • MQ Advanced container imagesaffected: 9.4.0.11-r1CVE List
  • MQ Advanced container imagesaffected: 9.4.0.11-r2CVE List
  • MQ Advanced container imagesaffected: 9.4.0.11-r3CVE List
  • MQ Advanced container imagesaffected: 9.4.0.12-r1CVE List
  • MQ Advanced container imagesaffected: 9.4.0.15-r1 through 9.4.0.15-r4CVE List
  • MQ Advanced container imagesaffected: 9.4.0.16-r1CVE List
  • MQ Advanced container imagesaffected: 9.4.0.16-r2CVE List
  • MQ Advanced container imagesaffected: 9.4.0.17-r1CVE List
  • MQ Advanced container imagesaffected: 9.4.0.17-r2CVE List
  • MQ Advanced container imagesaffected: 9.4.0.20-r1CVE List
  • MQ Advanced container imagesaffected: 9.4.0.21-r1CVE List
  • MQ Advanced container imagesaffected: 9.4.0.21-r2CVE List
  • MQ Advanced container imagesaffected: 9.4.0.25-r1 through 9.4.0.25-r3CVE List
  • MQ Advanced container imagesaffected: 9.4.0.26-r1CVE List
  • MQ Advanced container imagesaffected: 9.4.1.0-r1CVE List
  • MQ Advanced container imagesaffected: 9.4.1.0-r2CVE List
  • MQ Advanced container imagesaffected: 9.4.1.1-r1CVE List
  • MQ Advanced container imagesaffected: 9.4.2.0-r1CVE List
  • MQ Advanced container imagesaffected: 9.4.2.0-r2CVE List
  • MQ Advanced container imagesaffected: 9.4.2.1-r1CVE List
  • MQ Advanced container imagesaffected: 9.4.2.1-r2CVE List
  • MQ Advanced container imagesaffected: 9.4.3.0-r1CVE List
  • MQ Advanced container imagesaffected: 9.4.3.0-r2CVE List
  • MQ Advanced container imagesaffected: 9.4.3.1-r1 through 9.4.3.1-r3CVE List
  • MQ Advanced container imagesaffected: 9.4.4.0-r1CVE List

References 1