Medium 5.1Published Sep 25, 2026

CVE-2026-67407RabbitMQ: Incomplete fix for CVE-2026-44838: `escape_regex_char/1` does not escape `-`, leaving room for an MQTT topic permission bypass

Updated under an hour ago (2026-10-19 06:20 UTC)

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Every CVE for rabbitmq-server

Exploited in the last 30 days

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.

CVSS: 5.1 MEDIUM (v4.0, CNA)CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:N/SC:L/SI:H/SA:N
Weakness (CWE): CWE-862
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Analyzed
Record last updated: Sep 25, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

rabbitmq rabbitmq-server rabbitmq:server (from the name)	from 4.3.2, < 4.3.3; from 4.2.0, < 4.2.9; from 4.1.0, < 4.1.14; from 4.0.0, < 4.0.23	CNA record
broadcom rabbitmq_server broadcom:rabbitmq_server	from 4.0.0 before 4.0.23; from 4.1.0 before 4.1.14; from 4.2.0 before 4.2.9; from 4.3.0 before 4.3.3	NVD

References

https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-q46v-hrvq-hp24x-refsource-confirm, vendor-advisory, exploit, mitigation
https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.9x-refsource-misc, release-notes
https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.3x-refsource-misc, release-notes

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.