Medium · published September 25, 2026
RabbitMQ is a messaging and streaming broker. From 3.13.0 until 3.13.15, 4.0.20, 4.1.11, and 4.2.6, mechanisms/1 applied list_to_atom/1 to every colon-delimited token in an attacker-controlled auth_mechanism value, permanently consuming Erlang VM atoms and allowing the node to be crashed with a large request. Exploitation requires the Shovel or Federation plugin to be in use, and setting auth_mechanism requires the policymaker tag. This issue is fixed in versions 3.13.15, 4.0.20, 4.1.11, and 4.2.6.
| Product | Versions | Fixed in |
|---|---|---|
| broadcom/rabbitmq_server | ≥ 3.13.0, < 3.13.15 | 3.13.15 |
| broadcom/rabbitmq_server | ≥ 4.0.0, < 4.0.20 | 4.0.20 |
| broadcom/rabbitmq_server | ≥ 4.1.0, < 4.1.11 | 4.1.11 |
| broadcom/rabbitmq_server | ≥ 4.2.0, < 4.2.6 | 4.2.6 |