Executable Regular Expression Error Affecting rabbitmq-server4.3 package, versions <0:4.3.4-0.1.hum1


Severity

Recommended
0.0
high
0
10

Based on Red Hat Enterprise Linux security rating.

Threat Intelligence

EPSS
0.2% (10th percentile)

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  • Snyk IDSNYK-RHEL10-RABBITMQSERVER43-18380334
  • published29 Jul 2026
  • disclosed27 May 2026

Introduced: 27 May 2026

CVE-2026-44838  (opens in a new tab)
CWE-624  (opens in a new tab)

How to fix?

Upgrade RHEL:10 rabbitmq-server4.3 to version 0:4.3.4-0.1.hum1 or higher.
This issue was patched in RHSA-2026:45128.

NVD Description

Note: Versions mentioned in the description apply only to the upstream rabbitmq-server4.3 package and not the rabbitmq-server4.3 package as distributed by RHEL. See How to fix? for RHEL:10 relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1