SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2025-66481

Versions 0.5.1 and below are vulnerable to XSS attacks through improperly sanitized Mermaid content.

CRITICAL 9.6EPSS 0.58%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.58%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 3.1
9.6 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
EPSS
0.58% probability · 46th percentile
CISA KEV
Not listed
Weakness
CWE-79, CWE-80, CWE-94
Affected
thinkinai/deepchat
Source
security-advisories@github.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.