RCE in Thinkinai Deepchat
CVE-2025-66481
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.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.6 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.006 (45.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 45th percentile — 45.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: +0.000
Affected products
- Thinkinai Deepchat
- Thinkinaixyz Deepchat — versions <= 0.5.1
Weakness classification (CWE)
References
- github.com/ThinkInAIXYZ/deepchat/security/advisories/GHSA-h9f5-7hhf-fqm4 (Exploit, Vendor Advisory)
Frequently asked questions
- What is CVE-2025-66481?
- CVE-2025-66481 is a critical-severity vulnerability in Thinkinai Deepchat, classified under Cross-site Scripting. CVSS score: 9.6/10. Published 2025-12-09.
- How severe is CVE-2025-66481?
- Critical severity. CVSS v3 base score is 9.6 out of 10.