CVE-2026-82639

HighCVSS 7.5

Published: 30/08/2026(UTC)Updated: 10/09/2026(UTC)Translated: 30/08/2026(UTC)NVD NIST

Exploitation Probability (EPSS)

Low risk

0.30%

22th percentile - higher than 22% of all known CVEs

Summary

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.

Risk Assessment

Risk of exposing the OpenAI API key, potentially leading to unauthorized resource usage and financial costs.

Recommendation

Update NextChat to a version newer than 2.16.1 that fixes this vulnerability. Additionally, consider restricting access to the proxy endpoint.

Other vulnerabilities in NextChat

CVE-2026-105238High
A flaw has been found in ChatGPTNextWeb NextChat up to 2.16.1. This vulnerability affects the function proxyHandler of the file app/api/proxy.ts of the component Proxy Fallback Handler. This manipulation of the argument x-base-url causes server-side request forgery. It is possible to initiate the attack remotely. The exploit has been published and may be used. The pull request to fix this issue awaits acceptance.

Original NVD description (English source)

Vulnerability data from NVD (NIST) · CISA KEV · EPSS