CVE-2025-66481CRITICAL 9.6EPSS p37.7%

CVE-2025-66481CVE-2025-66481

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.

Scoring

CVSS 3.19.6 (CRITICAL)
VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
EPSS0.48% probability of exploitation · percentile 37.7% · 2026-06-18T12:00:27Z
Published2025-12-09
Last modified2025-12-11

Underlying weaknesses· 3

CWE-79CWE-80CWE-94

References

  1. https://github.com/ThinkInAIXYZ/deepchat/security/advisories/GHSA-h9f5-7hhf-fqm4
  2. https://github.com/ThinkInAIXYZ/deepchat/security/advisories/GHSA-h9f5-7hhf-fqm4

3

TypeTargetConfidenceTier
WeaknessImproper Neutralization of Input During Web Page Generation ('Cross-site Scripting')cwe-790%live
WeaknessImproper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)cwe-800%live
WeaknessImproper Control of Generation of Code ('Code Injection')cwe-940%live

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Nearest entities by semantic similarity across the cs-graph corpus.

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Sourced from NVD + FIRST.org EPSS. Curated for EU compliance use cases by Adam Lundqvist, Founder at SQUR.