CVE-2026-44838
BaseFortify
Publication date: 2026-05-27
Last updated on: 2026-05-27
Assigner: GitHub, Inc.
Description
Description
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| rabbitmq | rabbitmq_mqtt_plugin | From 4.2.0 (inc) to 4.2.4 (exc) |
| rabbitmq | rabbitmq_mqtt_plugin | 4.2.4 |
| rabbitmq | rabbitmq_mqtt_plugin | 4.3.0 |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-863 | The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability exists in RabbitMQ's MQTT plugin versions from 4.2.0 to before 4.2.4. The plugin uses regular expressions with variable substitution to enforce topic-level authorization, allowing administrators to restrict user access to specific topics based on client IDs.
However, the client_id used in these regex patterns is provided by the user in the MQTT CONNECT packet and is inserted into the regex without escaping special regex characters. This allows an authenticated MQTT user to inject regex operators, potentially bypassing the intended authorization restrictions.
The issue was fixed in RabbitMQ versions 4.2.4 and 4.3.0.
How can this vulnerability impact me? :
This vulnerability can allow an authenticated MQTT user to bypass topic-level authorization controls by injecting special regex characters into the client_id. As a result, the user may gain unauthorized access to topics they should not have permission to access.
This unauthorized access could lead to exposure of sensitive messaging data or unauthorized message publishing, potentially compromising the confidentiality and integrity of the messaging system.
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability, you should upgrade RabbitMQ to version 4.2.4 or later, or 4.3.0 or later, where the issue has been fixed.