---
cve: "CVE-2026-66067"
severity: "MEDIUM"
cvss: 6.0
epss: "2.9%"
vendor: "rabbitmq"
kev: false
exploited: false
published: "2026-09-23 21:16:58"
tags: [cve, security, medium]
source: tsecurity.de CVE-Dossier
exported: "2026-09-25T23:02:15+02:00"
---

# CVE-2026-66067

> 6.0 MEDIUM · 🧪 PoC

## Beschreibung

RabbitMQ is a messaging and streaming broker. Prior to versions 4.2.7 and 4.3.1, The stream open handler calls only check_vhost_access; it omits the node/vhost/user connection-limit checks that rabbit_reader performs for AMQP. A developer %% FIXME comment at the cited line explicitly acknowledges the gap. No compensating enforcement exists in connection tracking or elsewhere in rabbitmq_stream. An authenticated tenant can fully bypass operator-configured per-user and per-vhost connection caps by connecting via port 5552 instead of 5672. Preconditions include rabbitmq_stream plugin enabled Authenticated stream-protocol credentials Operator relies on per-user/per-vhost connection limits for tenant isolation. This issue is fixed in versions 4.2.7 and 4.3.1.

## CVSS-Vektor

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

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

## Patch verfügbar (OSV)

- b15fd2a3e5465cb6ed403d5a774ef61b1a391b89 (Commit)
- 49decca35e59d2cb774e5abd76412cee721308a5 (Commit)

## Referenzen

- <https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-hwqx-2gfg-89qf>
- <https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.7>
- <https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.1>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-66067) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_