---
cve: "CVE-2026-67411"
severity: "MEDIUM"
cvss: 6.0
epss: ""
vendor: "rabbitmq"
kev: false
exploited: false
published: "2026-09-25 17:17:13"
tags: [cve, security, medium]
source: tsecurity.de CVE-Dossier
exported: "2026-09-28T04:03:56+02:00"
---

# CVE-2026-67411

> 6.0 MEDIUM · 🧪 PoC

## Beschreibung

RabbitMQ is a messaging and streaming broker. From 3.13.0 until 3.13.18, 4.0.23, 4.1.14, 4.2.9, and 4.3.3, native MQTT and MQTT over WebSocket behind a trusted PROXY Protocol frontend could lose the proxy-derived client address before the MQTT authentication path checked loopback_users, causing the frontend-to-broker address to be treated as loopback. An attacker who can reach the trusted frontend and has valid credentials for a loopback-restricted account can therefore bypass the source-address restriction; the issue does not bypass password authentication. This issue is fixed in versions 3.13.18, 4.0.23, 4.1.14, 4.2.9, and 4.3.3.

## CVSS-Vektor

```
CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Hoch | good |
| 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-4r6f-9cpw-f6g6>
- <https://github.com/rabbitmq/rabbitmq-server/commit/a7528314840c4f8dc9904684f9f97ffa7aac6349>
- <https://github.com/rabbitmq/rabbitmq-server/commit/edbead0eabbd65925d0dc914a22d6a29e155e646>
- <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-2026-67411) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI WID (CSAF)_