Vulnerability · Published Sep 25, 2026 · Assigned by GitHub_M
CVE-2026-67222RabbitMQ: list_to_atom on auth_mechanism URI tokens in amqp_client
Medium 5.9
In plain English
A medium-severity uncontrolled resource consumption in rabbitmq-server from rabbitmq. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 25% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | rabbitmq-server | no fix listed | DEBIAN-CVE-2026-67222 |
| Debian:13 | rabbitmq-server | no fix listed | DEBIAN-CVE-2026-67222 |
| Debian:14 | rabbitmq-server | 4.3.0-2 | DEBIAN-CVE-2026-67222 |
| Ubuntu:22.04:LTS | rabbitmq-server | no fix listed | UBUNTU-CVE-2026-67222 |
| Ubuntu:24.04:LTS | rabbitmq-server | no fix listed | UBUNTU-CVE-2026-67222 |
| Ubuntu:26.04:LTS | rabbitmq-server | no fix listed | UBUNTU-CVE-2026-67222 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| rabbitmq | rabbitmq-server | >= 3.13.0, < 3.13.15>= 4.0.0, < 4.0.20>= 4.1.0, < 4.1.11>= 4.2.0, < 4.2.6 |
Weakness: CWE-400 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
References
- https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-85jr-6rr2-j73r x_refsource_CONFIRM
- https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.6 x_refsource_MISC