---
cve: "CVE-2026-82639"
severity: "HIGH"
cvss: 8.7
epss: "23.1%"
vendor: "ChatGPTNextWeb"
kev: false
exploited: false
published: "2026-08-30 14:17:03"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-08-31T16:38:41+02:00"
---

# CVE-2026-82639

> 8.7 HIGH · 🧪 PoC

## Beschreibung

NextChat versions from 2.15.8 through 2.16.1 contain an improper URL validation vulnerability in the proxy endpoint that allows attackers to obtain the server's OpenAI API key. The x-base-url header is validated using substring matching instead of hostname parsing, allowing any URL containing 'api.openai.com' to pass validation and receive the server's credentials in the Authorization header.

## CVSS-Vektor

```
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/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 |

## Referenzen

- <https://github.com/ChatGPTNextWeb/NextChat/issues/6814>
- <https://github.com/ChatGPTNextWeb/NextChat>
- <https://github.com/ChatGPTNextWeb/NextChat/blob/v2.16.1/app/api/proxy.ts>
- <https://www.vulncheck.com/advisories/nextchat-2.15.8-through-2.16.1-openai-api-key-disclosure>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-82639) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_