CVE-2026-82639 NextChat 2.15.8 through 2.16.1 OpenAI API Key Disclosure
Attackers can steal the server's OpenAI API key by exploiting improper URL validation in the proxy endpoint of NextChat.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-82639?
CVE-2026-82639 is a high-severity vulnerability in ChatGPTNextWeb NextChat, published on 30 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Weakness: CWE-20
Which versions are affected by CVE-2026-82639?
How do I fix CVE-2026-82639?
No fix has been published for CVE-2026-82639 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-82639 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-82639 exists.
Sources
Also known as GHSA-87fx-h8m6-gxwv.