Resource exhaustion in RabbitMQ Server - CVE-2026-67226
Published: July 24, 2026 / Updated: September 28, 2026
Vulnerability identifier: #VU139298
CSH Severity: Low
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-67226
CWE-ID: CWE-400
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to cause a denial of service.
The vulnerability exists due to uncontrolled resource consumption in the PUT /api/users tags list handling in rabbit_auth_backend_internal.erl when processing a user-supplied tags list. A remote privileged user can send a specially crafted request with a large number of unique tag strings to cause a denial of service.
The issue can also be triggered when importing definitions.
Affected software
RabbitMQ Server
How to mitigate CVE-2026-67226
Install security update from vendor's website.
RabbitMQ Server - addressed in versions 4.0.22, 4.1.14, 4.2.7