Input validation error in RabbitMQ Server - CVE-2026-67418
Published: August 18, 2026
Vulnerability identifier: #VU143938
CSH Severity: Low
CVSS v4: 5.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-67418
CWE-ID: CWE-20
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 improper input validation in the MQTT 5 property parser and outbound PUBLISH property serializer when processing a crafted MQTT 5 PUBLISH packet containing an inapplicable property. A remote user can send a specially crafted PUBLISH message to cause a denial of service.
MQTT or Web MQTT must be enabled, and exploitation requires a separately authenticated MQTT 5 or Web MQTT subscriber on a matching topic or subscription filter.
Affected software
RabbitMQ Server
How to mitigate CVE-2026-67418
Install security update from vendor's website.
RabbitMQ Server - addressed in versions 3.13.19, 4.0.24, 4.1.15, 4.2.10, 4.3.5