RabbitMQ all versions prior to 3.8.16 are prone to a denial of service vulnerability due to improper input validation in AMQP 1.0 client connection endpoint. A malicious user can exploit the vulnerability by sending malicious AMQP messages to the target RabbitMQ instance having the AMQP 1.0 plugin enabled.
https://tanzu.vmware.com/security/cve-2021-22116
https://lists.debian.org/debian-lts-announce/2021/07/msg00011.html