---
cve: "CVE-2026-67407"
severity: "MEDIUM"
cvss: 5.1
epss: ""
vendor: "rabbitmq"
kev: false
exploited: false
published: "2026-09-25 17:17:12"
tags: [cve, security, medium]
source: tsecurity.de CVE-Dossier
exported: "2026-09-28T08:17:13+02:00"
---

# CVE-2026-67407

> 5.1 MEDIUM · 🧪 PoC

## Beschreibung

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.

## CISA-Anreicherung (vulnrichment/ADP)

- CISA-SSVC (Coordinator, v2.0.3):
  - Exploitation: **none**
  - Automatable: **no**
  - Technical Impact: **partial**

## CVSS-Vektor

```
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
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Gering | warn |
| UI Interaktion | Keine | bad |

## Patch verfügbar (OSV)

- 1d284b2d2a1e2f845ad22b0d5ee38ec372d50802 (Commit)
- 47d6d6457c7d1a440daed643cb7d76bba313e79c (Commit)

## Referenzen

- <https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-q46v-hrvq-hp24>
- <https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.9>
- <https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.3>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-67407) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI WID (CSAF)_