In Spring AMQP versions 2.2.0 – 2.2.18 and 2.3.0 – 2.3.10, the Spring AMQP Message object, in its toString() method, will deserialize a body for a message with content type application/x-java-serialized-object. It is possible to construct a malicious java.util.Dictionary object that can cause 100% CPU usage in the application if the toString() method is called.