CVE-2025-66481

CRITICAL

DeepChat <0.5.1 - XSS

Title source: llm
STIX 2.1

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.

Scores

CVSS v3 9.6
EPSS 0.0037
EPSS Percentile 58.6%
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