CVE-2025-66481

Name: CVE-2025-66481
Creator: NVD / NIST
Published: 2025-12-09T01:16:55.14+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.6/10EPSS 0.48%

Last modified Jun 17, 2026

CVE-2025-66481 is a critical-severity vulnerability rated 9.6/10 on the CVSS scale. 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. EPSS estimates a 0.48% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

9.6/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

EPSS Probability

0.48%

37.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Thinkinai	Deepchat	<= 0.5.1

References

https://github.com/ThinkInAIXYZ/deepchat/security/advisories/GHSA-h9f5-7hhf-fqm4Exploit, Vendor Advisory
https://github.com/ThinkInAIXYZ/deepchat/security/advisories/GHSA-h9f5-7hhf-fqm4Exploit, Vendor Advisory

Timeline

Published: Dec 9, 2025
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2025-66481?

How severe is CVE-2025-66481?

CVE-2025-66481 has a CVSS score of 9.6/10 (CRITICAL severity). The EPSS model estimates a 0.48% probability of exploitation in the next 30 days.

How do I fix CVE-2025-66481?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2025-66481?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST