CVE-2026-66075

RabbitMQ is a messaging and streaming broker. Prior to versions 3.13.15, 4.0.20, 4.1.11, 4.2.6, and 4.3.1, is_authorized/2 for the /federation-links/.../restart route uses is_authorized_monitor (accepts the monitoring tag), while allowed_methods permits DELETE and delete_resource/2 triggers rabbit_federation_link_sup:restart. There is no per-method elevation check and no comment marking it intentional. A read-only monitoring user can restart any federation link , a state-changing operation that disrupts message flow. Preconditions include rabbitmq_federation + rabbitmq_federation_management plugins enabled Attacker has credentials with the monitoring tag. This issue is fixed in versions 3.13.15, 4.0.20, 4.1.11, 4.2.6, and 4.3.1.

• https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.6Release Notes
• https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.1Release Notes
• https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-g5v3-w5xg-62q2Vendor Advisory