NextChat vulnerability

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.

Published 5 Oct 2026Updated 5 Oct 20267 sources
CVSS 5.5

What happened

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.

Affected versions

NextChat: 2.16.0; 2.16.1 Fixed: See vendor advisory.

Why it matters

Review the vendor advisory and exposure of the affected product to determine operational impact.

Detection & mitigation

  • Apply vendor-provided updates or mitigations.
  • Review affected product exposure and access logs.

Public PoC references

No public PoC reference has passed the current publication threshold.