CVE-2025-66481

DeepChat's Incomplete XSS Fix Allows RCE through Mermaid Content

Published Dec 9, 2025 CVSS 3.1 · 9.7 Critical EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
CPEs cpe:2.3:a:thinkinai:deepchat:*:*:*:*:*:*:*:*
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Thinkinai
Thinkinai deepchat
Vendors & Products Thinkinai
Thinkinai deepchat
Type Values Removed Values 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.
Title DeepChat's Incomplete XSS Fix Allows RCE through Mermaid Content
Weaknesses CWE-79
CWE-80
CWE-94
References
Metrics cvssV3_1

{'score': 9.7, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Dec 9, 2025, 4:03 PM
Reserved
Dec 2, 2025, 5:09 PM
Status
Analyzed
Published
Dec 9, 2025, 1:16 AM
Modified
Oct 7, 2026, 8:10 PM