CVE-2026-67229: Rabbitmq Rabbitmq-Server

Medium severity, CVSS 6.9. EPSS: 0.3% chance of exploitation in the next 30 days.

RabbitMQ is a messaging and streaming broker. Prior to versions 3.13.15, 4.0.20, 4.1.11, 4.2.6, and 4.3.0, add_vhost/2 calls rabbit_data_coercion:atomize_keys/1 (the unsafe variant using binary_to_atom) on the vhost metadata map. The 20 MB management body limit fits ~1M+ short keys. Admin-only. An administrator importing a crafted definitions file can crash the node in a single request: a vhosts entry with ~1M unique metadata keys exhausts the atom table during import. Preconditions include administrator tag. This issue is fixed in versions 3.13.15, 4.0.20, 4.1.11, 4.2.6, and 4.3.0.

Affected products

• Rabbitmq Rabbitmq-Server: from 3.13.0, before 3.13.15 (fixed in 3.13.15); from 4.0.0, before 4.0.20 (fixed in 4.0.20); from 4.1.0, before 4.1.11 (fixed in 4.1.11); from 4.2.0, before 4.2.6 (fixed in 4.2.6)

Published 2026-09-23. Last modified 2026-09-24.