Auth bypass in Chatgptnextweb Nextchat

CVE-2026-7644

A vulnerability has been found in ChatGPTNextWeb NextChat up to 2.16.1. Affected is the function addMcpServer of the file app/mcp/actions.ts. The manipulation leads to improper authorization. Remote exploitation of the attack is possible. The exploit has been disclosed to the public and may be used. The project was informed of the problem early through an issue report but has not responded yet.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.3 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L.

EPSS exploit prediction

EPSS: 0.005 (41.4th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 41st percentile — 41.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-7644: held from 0.003 to 0.005.

EPSS over last 30 days · oldest: 0.003 · newest: 0.005 · change: +0.002

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-7644?
CVE-2026-7644 is a high-severity vulnerability in Chatgptnextweb Nextchat, classified under Incorrect Privilege Assignment. CVSS score: 7.3/10. Published 2026-05-02.
How severe is CVE-2026-7644?
High severity. CVSS v3 base score is 7.3 out of 10.