---
cve: "CVE-2026-67409"
severity: "HIGH"
cvss: 8.2
epss: "0.5%"
vendor: "rabbitmq"
kev: false
exploited: false
published: "2026-09-25 17:17:12"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-10-09T19:13:07+02:00"
---

# CVE-2026-67409

> 8.2 HIGH · 🧪 PoC

## Beschreibung

RabbitMQ is a messaging and streaming broker. From 3.13.0 until 4.3.3, 4.2.9, 4.1.14, 4.0.23, and 3.13.18, JWKS Fetch Ignores HTTP Response Status Code - Signing Key Destruction Causes Authentication DoS (CWE-252). the JWKS key fetching mechanism in uaajwt.erl does not validate the HTTP response status code when downloading signing keys from the OAuth2 provider's JWKS endpoint. Non-200 responses (including 4xx and 5xx errors) are processed identically to successful responses. When the JWKS endpoint returns an error response with a valid-JSON body that lacks a keys field, all previously cached signing keys are destroyed, causing a persistent authentication denial of Files: deps/rabbitmqauthbackendoauth2/src/uaajwt.erl, lines 50-63 deps/rabbitmqauthbackendoauth2/src/uaajwks.erl, lines 5-7 deps/rabbitmqauthbackendoauth2/src/rabbitoauth2provider.erl, lines 98-107 Bug 1: HTTP status code ignored (uaajwt.erl:50-63): The Erlang httpc module returns {ok, {{HttpVersion, StatusCode, ReasonPhrase}, Headers, Body}}. The pattern {ok, {, , JwksBody}} matches ANY successful HTTP transaction Persistent authentication DoS: Once keys are destroyed, ALL OAuth2/JWT authentication fails for all users until a new successful JWKS refresh occurs Amplification: A single attacker can deny access to all legitimate OAuth2 users across the entire RabbitMQ. This issue is fixed in versions 4.3.3, 4.2.9, 4.1.14, 4.0.23, and 3.13.18.

## CISA-Anreicherung (vulnrichment/ADP)

- CISA-SSVC (Coordinator, v2.0.3):
  - Exploitation: **poc**
  - Automatable: **no**
  - Technical Impact: **partial**

## CVSS-Vektor

```
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/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 | Keine | bad |
| UI Interaktion | Keine | bad |

## Schwachstellen-Klasse

- **CWE-252** — Unchecked Return Value
  The product does not check the return value from a method or function, which can prevent it from detecting unexpected states and conditions.

## Patch verfügbar (OSV)

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

## BSI-Hinweise (deutsch)

- [RabbitMQ: Mehrere Schwachstellen](https://wid.cert-bund.de/portal/wid/sicherheitshinweis/WID-SEC-W-2026-2485) — _BSI-Einstufung: mittel_
  Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in RabbitMQ ausnutzen, um Denial-of-Service-Angriffe durchzuführen, Autorisierungs- und Mandantengrenzen zu umgehen, Daten zu manipulieren oder offenzulegen und Cross Site Scripting Angriffe durchzuführen.

## Referenzen

- <https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-qw3h-qqm9-jrw8>
- <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/sicherheitsluecken/cve-2026-67409/) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI WID (CSAF)_