---
id: CVE-2025-66481
title: >-
  DeepChat is an open-source AI chat platform that supports cloud models and
  LLMs
summary: >-
  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 in…
severity: critical
cvss: 9.6
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H'
cwe:
  - CWE-79
  - CWE-80
  - CWE-94
  - CWE-79
vendor: thinkinai
product: deepchat
affected:
  - deepchat <= 0.5.1
published: '2025-12-09'
updated: '2026-10-07'
sourceUpdated: '2026-10-07T20:10:01.970'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-66481'
references:
  - url: >-
      https://github.com/ThinkInAIXYZ/deepchat/security/advisories/GHSA-h9f5-7hhf-fqm4
    label: security-advisories@github.com
  - url: >-
      https://github.com/ThinkInAIXYZ/deepchat/security/advisories/GHSA-h9f5-7hhf-fqm4
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
epss: 0.0058
epssPercentile: 0.45865
ingestedAt: '2026-10-07T20:46:46.780Z'
---

## Overview

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.

## Affected

- `deepchat <= 0.5.1`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.