CVE-2025-66481 DeepChat's Incomplete XSS Fix Allows RCE through Mermaid Content
Attackers can achieve remote code execution on victim machines via XSS in DeepChat's Mermaid content rendering due to insufficient sanitization.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2025-66481?
CVE-2025-66481 is a critical cross-site scripting vulnerability in ThinkInAIXYZ deepchat, published on 9 Dec 2025. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official 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.
Which versions are affected by CVE-2025-66481?
It affects 1 product.
Products include Thinkinai Deepchat.
How do I fix CVE-2025-66481?
No fix has been published for CVE-2025-66481 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2025-66481 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-66481 exists.
Other vulnerabilities in ThinkInAIXYZ deepchat
- CVE-2025-67744 Mermaid XSS vulnerability leads to Remote Code Execution
- CVE-2025-66222 DeepChat Cross-Site Scripting(XSS) escalate to Remote Code Execution(RCE)
- CVE-2025-58768 DeepChat's Mermaid rendering has XSS leading to RCE
- CVE-2025-55733 DeepChat One-click Remote Code Execution through Custom URL Handling
Sources
Also known as GHSA-h9f5-7hhf-fqm4.