CVE-2026-66073 is a vulnerability in RabbitMQ server versions prior to 3.9.23-5.oe2203sp4 and certain 4.x versions that allows atom table exhaustion via the management API node field. This flaw permits any user with the management tag and access to one virtual host to leak atoms permanently, potentially crashing the Erlang VM after approximately 900,000 requests and causing service disruption for all tenants. The issue arises because the node field value is converted to an atom without proper cluster membership checks, leading to resource exhaustion. This vulnerability has been fixed in RabbitMQ versions 3.9.23-5.oe2203sp4, 3.13.15, 4.0.20, 4.1.11, and 4.2.6.