9.6
CRITICAL CVSS 3.1
CVE-2025-66481
DeepChat's Incomplete XSS Fix Allows RCE through Mermaid Content
Description

DeepChat is an open-source AI chat platform that supports cloud models and LLMs. Versions 0.5.1 and below are vulnerable to XSS attacks through improperly sanitized Mermaid content. The recent security patch for MermaidArtifact.vue is insufficient and can be bypassed using unquoted HTML attributes combined with HTML entity encoding. Remote Code Execution is possible on the victim's machine via the electron.ipcRenderer interface, bypassing the regex filter intended to strip dangerous attributes. There is no fix at time of publication.

INFO

Published Date :

Dec. 9, 2025, 1:16 a.m.

Last Modified :

Dec. 9, 2025, 1:16 a.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2025-66481 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 CRITICAL [email protected]
Solution
Update DeepChat to patch XSS vulnerabilities in Mermaid content rendering.
  • Apply the latest security patch for DeepChat.
  • Sanitize all user-provided Mermaid content thoroughly.
  • Implement stricter input validation for HTML attributes.
  • Update the electron.ipcRenderer interface handling.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2025-66481.

URL Resource
https://github.com/ThinkInAIXYZ/deepchat/security/advisories/GHSA-h9f5-7hhf-fqm4
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2025-66481 is associated with the following CWEs:

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2025-66481 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2025-66481 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Dec. 09, 2025

    Action Type Old Value New Value
    Added Description DeepChat is an open-source AI chat platform that supports cloud models and LLMs. Versions 0.5.1 and below are vulnerable to XSS attacks through improperly sanitized Mermaid content. The recent security patch for MermaidArtifact.vue is insufficient and can be bypassed using unquoted HTML attributes combined with HTML entity encoding. Remote Code Execution is possible on the victim's machine via the electron.ipcRenderer interface, bypassing the regex filter intended to strip dangerous attributes. There is no fix at time of publication.
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
    Added CWE CWE-79
    Added CWE CWE-94
    Added CWE CWE-80
    Added Reference https://github.com/ThinkInAIXYZ/deepchat/security/advisories/GHSA-h9f5-7hhf-fqm4
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
Vulnerability Scoring Details
Base CVSS Score: 9.6
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact