---
cve: "CVE-2026-66005"
severity: "MEDIUM"
cvss: 5.3
epss: "0.2%"
vendor: "janhq"
kev: false
exploited: false
published: "2026-07-24 15:19:07"
tags: [cve, security, medium]
source: tsecurity.de CVE-Dossier
exported: "2026-09-20T22:13:11+02:00"
---

# CVE-2026-66005

> 5.3 MEDIUM · 🧪 PoC

## Beschreibung

Jan through 0.8.4, fixed in commit 3e1c1e7, contains a CORS misconfiguration vulnerability in its local API server that allows network-adjacent attackers to bypass trusted host restrictions by exploiting the server's replacement of user-configured trusted hosts with a wildcard that reflects arbitrary origins with credentials. Attackers on the local network or using DNS rebinding can reach the unauthenticated OpenAI-compatible API to perform inference, enumerate models, invoke MCP tools, and read cross-origin responses.

## CVSS-Vektor

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

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

## Patch verfügbar (OSV)

- 5f30aee467f08941964a83f946e2663e7ae0e01f (Commit)
- 3e1c1e724f696620d89bb4a9cc18a380e0753757 (Commit)

## Referenzen

- <https://github.com/janhq/jan/issues/8453>
- <https://github.com/janhq/jan/pull/8506>
- <https://github.com/janhq/jan/commit/3e1c1e724f696620d89bb4a9cc18a380e0753757>
- <https://www.vulncheck.com/advisories/jan-local-api-server-cors-origin-reflection-via-binding>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-66005) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_