CVE-2026-67222

RabbitMQ: list_to_atom on auth_mechanism URI tokens in amqp_client

State: Published
Severity: 5.9 Medium
Published: Sep 25, 2026
Updated: Sep 28, 2026
Reserved: Jul 28, 2026

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.

Scores

CVSS	Score	Vector	Source
4.0	5.9 Medium	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	GitHub_M

Weaknesses

CWE-400 Uncontrolled Resource Consumption

Affected Products

Product	Versions
rabbitmq-serverrabbitmq	>= 3.13.0, < 3.13.15Affected >= 4.0.0, < 4.0.20Affected >= 4.1.0, < 4.1.11Affected >= 4.2.0, < 4.2.6Affected

References

Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.