RabbitMQ up to 4.0.22/4.1.13/4.2.8/4.3.2 MQTT Topic Permission escaperegexchar clientid privileges management

Summaryinfo

A vulnerability marked as critical has been reported in RabbitMQ up to 4.0.22/4.1.13/4.2.8/4.3.2. Affected is the function escaperegexchar of the component MQTT Topic Permission. This manipulation of the argument clientid causes privileges management. This vulnerability is registered as CVE-2026-67407. Remote exploitation of the attack is possible. No exploit is available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical was found in RabbitMQ up to 4.0.22/4.1.13/4.2.8/4.3.2. Affected by this vulnerability is the function escaperegexchar of the component MQTT Topic Permission. The manipulation of the argument clientid with an unknown input leads to a privileges management vulnerability. The CWE definition for the vulnerability is CWE-269. The product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

RabbitMQ is a messaging and streaming broker. From 4.0.0 until 4.3.3 and 4.2.9 and 4.1.14 and 4.0.23, Incomplete fix for CVE-2026-44838: escaperegexchar/1 does not escape -, leaving room for an MQTT topic permission bypass. the CVE-2026-44838 fix made expandtopicpermission/2 escape regex metacharacters in expanded topic-permission variables (escaperegex(V)), but escaperegexchar/1 escapes \ ^ $ . | ? + ( ) [ ] { } and omits -. When a topic permission template places {clientid} inside a [...] character class A low-privileged authenticated MQTT user controlling its clientid can broaden topic authorization (read and write) when templates embed {clientid} in a [...] This issue is fixed in versions 4.3.3 and 4.2.9 and 4.1.14 and 4.0.23.

The advisory is shared at github.com. This vulnerability is known as CVE-2026-67407 since 07/29/2026. The exploitation appears to be easy. The attack can be launched remotely. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1068 for this issue.

Upgrading to version 4.0.23, 4.1.14, 4.2.9 or 4.3.3 eliminates this vulnerability.

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Productinfo

Name

• RabbitMQ

Version

• 4.0.0
• 4.0.1
• 4.0.2
• 4.0.3
• 4.0.4
• 4.0.5
• 4.0.6
• 4.0.7
• 4.0.8
• 4.0.9
• 4.0.10
• 4.0.11
• 4.0.12
• 4.0.13
• 4.0.14
• 4.0.15
• 4.0.16
• 4.0.17
• 4.0.18
• 4.0.19
• 4.0.20
• 4.0.21
• 4.0.22
• 4.1.0
• 4.1.1
• 4.1.2
• 4.1.3
• 4.1.4
• 4.1.5
• 4.1.6
• 4.1.7
• 4.1.8
• 4.1.9
• 4.1.10
• 4.1.11
• 4.1.12
• 4.1.13
• 4.2.0
• 4.2.1
• 4.2.2
• 4.2.3
• 4.2.4
• 4.2.5
• 4.2.6
• 4.2.7
• 4.2.8
• 4.3.0
• 4.3.1
• 4.3.2

CPE 2.3info

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CPE 2.2info

• 🔒
• 🔒
• 🔒

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