Interpretation Conflict in RabbitMQ Server - #VU143941

 

Interpretation Conflict in RabbitMQ Server - #VU143941

Published: August 18, 2026


Vulnerability identifier: #VU143941
CSH Severity: Low
CVSS v4: 5.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-436
Exploitation vector: Remote access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a remote user to spoof the publisher identity presented to consumers.

The vulnerability exists due to interpretation conflict in the AMQP 1.0 server parser and message conversion path when processing AMQP 1.0 messages with a properties section placed after the first body section. A remote user can publish a specially crafted message with a forged late user-id to spoof the publisher identity presented to consumers.

Exploitation requires the ability to authenticate over AMQP 1.0, write to the target exchange or queue, and reach consumers that accept out-of-order sections or consume the message through a cross-protocol conversion path. Consumers that rely on the message user-id as an authenticated identity signal are affected.


Affected software

RabbitMQ Server

Remediation

Install security update from vendor's website.

RabbitMQ Server - update to 4.3.5

External References

Related Security Bulletins