The XML4J parser in IBM WebSphere Message Broker 6.1 before 6.1.0.12, 7.0 before 7.0.0.7, and 8.0 before 8.0.0.4 and IBM Integration Bus 9.0 before 9.0.0.1 allows remote attackers to cause a denial of service (memory consumption) via a crafted XML document that triggers expansion for many entities.