CVE-2025-66222

Name: CVE-2025-66222
Creator: NVD / NIST
Published: 2025-12-03T19:15:58.237+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.6/10EPSS 0.51%

Last modified Jun 17, 2026

CVE-2025-66222 is a critical-severity vulnerability rated 9.6/10 on the CVSS scale. 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. EPSS estimates a 0.51% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

9.6/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

EPSS Probability

0.51%

39.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Thinkinai	Deepchat	<= 0.5.0

References

https://github.com/ThinkInAIXYZ/deepchat/commit/371ca7b42e3685aee6e3f0c61e85277ed1ff4db7Patch
https://github.com/ThinkInAIXYZ/deepchat/security/advisories/GHSA-v8v5-c872-mf8rExploit, Vendor Advisory

Timeline

Published: Dec 3, 2025
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2025-66222?

How severe is CVE-2025-66222?

CVE-2025-66222 has a CVSS score of 9.6/10 (CRITICAL severity). The EPSS model estimates a 0.51% probability of exploitation in the next 30 days.

How do I fix CVE-2025-66222?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2025-66222?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST