Connection shutdown via malformed body frame

Denial of service in RabbitMQ Java Client before 5.31.0 allows remote authenticated users to close a client connection via malformed AMQP frames. In CommandAssembler.consumeBodyFrame, the client subtracts a peer-controlled FRAME_BODY payload length from remainingBodyBytes before checking that the fragment fits the header-declared body size, which drives the counter negative and throws a raw UnsupportedOperationException instead of MalformedFrameException. Exploitation requires the client to connect to a malicious or compromised broker on a nonzero channel; the result is connection teardown and service interrupt for work using that connection, with no reported code execution, memory corruption, or data disclosure.