BaseFortify

Publication date: 2025-12-03

Last updated on: 2025-12-05

Assigner: GitHub, Inc.

Description

DeepChat is a smart assistant uses artificial intelligence. In 0.5.0 and earlier, there is a Stored Cross-Site Scripting (XSS) vulnerability in the Mermaid diagram renderer allows an attacker to execute arbitrary JavaScript within the application context. By leveraging the exposed Electron IPC bridge, this XSS can be escalated to Remote Code Execution (RCE) by registering and starting a malicious MCP (Model Context Protocol) server.

CVSS Scores

EPSS Scores

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Meta Information

Published

2025-12-03

Last Modified

2025-12-05

Generated

2026-07-06

AI Q&A

2025-12-03

EPSS Evaluated

2026-07-05

NVD

CVE-2025-66222

EUVD

EUVD-2025-201091

Affected Vendors & Products

Vendor	Product	Version / Range
thinkinai	deepchat	to 0.5.0 (inc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-94	The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.
CWE-79	The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

Attack-Flow Graph

Executive Summary

This vulnerability is a Stored Cross-Site Scripting (XSS) issue in the Mermaid diagram renderer used by DeepChat version 0.5.0 and earlier. An attacker can inject malicious JavaScript code that executes within the application's context. Furthermore, by exploiting the exposed Electron IPC bridge, the attacker can escalate this XSS vulnerability to Remote Code Execution (RCE) by registering and starting a malicious Model Context Protocol (MCP) server.

Impact Analysis

This vulnerability can have severe impacts including unauthorized execution of arbitrary JavaScript code within the application, which can lead to data theft, session hijacking, or other malicious actions. Additionally, the escalation to Remote Code Execution (RCE) allows an attacker to execute arbitrary code on the host system, potentially leading to full system compromise, data loss, or further attacks within the environment.

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