Inefficient Algorithmic Complexity in RabbitMQ Server - CVE-2026-67419
Published: August 18, 2026
Vulnerability identifier: #VU143939
CSH Severity: Low
CVSS v4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-67419
CWE-ID: CWE-407
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 inefficient algorithmic complexity in the topic exchange routing matcher when processing binding keys with consecutive `#` wildcard segments and comparable-depth routing keys. A remote user can declare a queue binding with adjacent `#` segments and publish a matching routing key to cause a denial of service.
The issue can allocate a large intermediate duplicate destination list before deduplication, and user interaction is not required.
Affected software
RabbitMQ Server
How to mitigate CVE-2026-67419
Install security update from vendor's website.
RabbitMQ Server - update to 4.3.5