IBM MQ 7.1.0.0 - 7.1.0.9, 7.5.0.0 - 7.5.0.9, 8.0.0.0 - 8.0.0.11, 9.0.0.0 - 9.0.0.6, 9.1.0.0 - 9.1.0.2, and 9.1.1 - 9.1.2 is vulnerable to a denial of service attack caused by a memory leak in the clustering code. IBM X-Force ID: 158337.