CVE-2025-66481
CRITICALdeepchat < 0.5.1 - Stored Cross-Site Scripting via Mermaid Content Bypass
Title source: llmDescription
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.
References (1)
Core 1
Core References
Vendor Advisory, Exploit x_refsource_confirm
https://github.com/ThinkInAIXYZ/deepchat/security/advisories/GHSA-h9f5-7hhf-fqm4
Scores
CVSS v3
9.6
EPSS
0.0048
EPSS Percentile
37.6%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
CISA SSVC
Vulnrichment
Exploitation
poc
Automatable
no
Technical Impact
total
Details
CWE
CWE-80
CWE-94
CWE-79
Status
published
Products (1)
thinkinai/deepchat
< 0.5.1
Published
Dec 09, 2025
Tracked Since
Feb 18, 2026