RabbitMQ is a messaging and streaming broker. From 3.13.0 until 3.13.15, 4.0.20, 4.1.11, and 4.2.6, the stream protocol stored the FrameMax value negotiated during the Tune handshake but did not compare it with an inbound frame's declared length before buffering the frame. With the stream plugin enabled, a remote client could therefore cause excessive memory pressure and denial of service by declaring an oversized frame. This issue is fixed in versions 3.13.15, 4.0.20, 4.1.11, and 4.2.6.