An unauthenticated client can trigger denial of service by issuing specially crafted wire protocol messages, which cause the message decompressor to incorrectly allocate memory. This issue affects: MongoDB Inc. MongoDB Server v4.2 versions prior to 4.2.1; v4.0 versions prior to 4.0.13; v3.6 versions prior to 3.6.15; v3.4 versions prior to 3.4.24.