CVE-2026-67222 RabbitMQ: list_to_atom on auth_mechanism URI tokens in amqp_client
Attacker with policymaker tag can crash RabbitMQ node via atom exhaustion in auth_mechanism if Shovel or Federation plugins are enabled.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-67222?
CVE-2026-67222 is a medium-severity denial of service vulnerability in Broadcom Rabbitmq Server, published on 25 Sep 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Official description
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.
Weakness: CWE-400
Which versions are affected by CVE-2026-67222?
1 open source package ship an affected version, including rabbitmq. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
rabbitmq Bitnami | From 3.13.0 | 3.13.15, 4.0.20, 4.1.11, 4.2.6 |
Products include Broadcom Rabbitmq Server.
How do I fix CVE-2026-67222?
Upgrade rabbitmq to a fixed version for your release line: 3.13.15, 4.0.20, 4.1.11 or 4.2.6.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-67222 being exploited?
There is no known exploitation of CVE-2026-67222 in the wild and no public exploit code.
Other vulnerabilities in Broadcom Rabbitmq Server
- CVE-2016-9877 Auth bypass in Pivotal RabbitMQ 3.x before 3.5.8 and 3.6.x before 3.6.6; RabbitMQ for PCF 1.5.x before 1.5.20, 1.6.x before 1.6.12 and 1.7.x before 1.7.7
- CVE-2026-67404 RabbitMQ: OAuth2 silent verify_none fallback for JWKS fetch
- CVE-2026-67231 RabbitMQ: Trust-store whitelist by Issuer+Serial only
- CVE-2026-57219 Information disclosure in rabbitmq-server
- CVE-2026-67236 RabbitMQ: Plaintext username:password stored in an insecure cookie after successful POST /login
Sources
Also known as AZL-105750, BIT-rabbitmq-2026-67222, DEBIAN-CVE-2026-67222, GHSA-85jr-6rr2-j73r, UBUNTU-CVE-2026-67222.