CVE-2026-44838
MEDIUM
MEDIUM
Priority: 0.01
BB Relevance:
61/100
Published: 2026-05-27
Modified: 2026-10-26
First seen: 2026-10-29
Status: active
Attack Surface
Network
Low Complexity
No Interaction
CVSS Vector Breakdown
AV:
Network
AC:
Low
PR:
Low
UI:
None
S:
X
AT:
Present
VC:
Low
VI:
Low
VA:
Low
Description
RabbitMQ is a messaging and streaming broker. From 4.2.0 to before 4.2.4, RabbitMQ's MQTT plugin allows for topic-level authorization using regular expressions with variable substitution. Administrators can create patterns such as ^{client_id}-sensors$ to restrict user access to topics that include their client ID. However, the client_id is provided by the user in the MQTT CONNECT packet and is inserted into the regex pattern without escaping special regex characters. This flaw enables an authenticated MQTT user to inject regex operators to bypass authorization. This vulnerability is fixed in 4.2.4 and 4.3.0.
Weakness Classification (1)
Affected Software (1)
| Vendor | Product | Version |
|---|---|---|
| broadcom | rabbitmq_server | 4.2.0 – 4.2.4 |
References & Advisories (1)
Vendor Advisory