CVE-2025-67744: Thinkinai Deepchat RCE Vulnerability

CVE-2025-67744 Overview

CVE-2025-67744 is a critical security vulnerability affecting DeepChat, an open-source artificial intelligence agent platform that unifies models, tools, and agents. The vulnerability exists in the Mermaid diagram rendering component and allows arbitrary JavaScript execution. Due to the exposure of the Electron IPC renderer to the DOM, this Cross-Site Scripting (XSS) flaw escalates to full Remote Code Execution (RCE), allowing an attacker to execute arbitrary system commands on the victim's machine.

Critical Impact

This vulnerability chains XSS with an exposed Electron IPC interface, enabling complete system compromise through arbitrary command execution. Attackers can leverage malicious Mermaid diagrams to gain full control over affected systems.

Affected Products

• Thinkinai DeepChat versions prior to 0.5.3
• DeepChat installations with Mermaid diagram rendering enabled
• Electron-based DeepChat desktop applications

Discovery Timeline

• December 16, 2025 - CVE-2025-67744 published to NVD
• January 02, 2026 - Last updated in NVD database

Technical Details for CVE-2025-67744

Vulnerability Analysis

This vulnerability is classified as Code Injection (CWE-94) and represents a severe security flaw in DeepChat's architecture. The issue arises from two concurrent security weaknesses that, when combined, create a critical attack chain.

The first weakness involves unsafe Mermaid configuration that fails to properly sanitize user-supplied diagram content, allowing the injection of arbitrary JavaScript code. The second weakness stems from the Electron IPC (Inter-Process Communication) interface being improperly exposed to the DOM renderer context. In properly secured Electron applications, the IPC bridge should be isolated to prevent web content from accessing system-level functionality.

When an attacker crafts a malicious Mermaid diagram containing JavaScript payloads, the unsanitized content executes within the renderer process. Because the IPC interface is accessible from this context, the injected JavaScript can invoke privileged IPC methods, effectively bridging the gap between web-based XSS and native system command execution.

Root Cause

The root cause of CVE-2025-67744 lies in two fundamental security oversights:

1. Unsafe Mermaid Configuration: The Mermaid diagram library was configured without proper sanitization of user-supplied content, allowing script injection through specially crafted diagram definitions.

2. Exposed Electron IPC Interface: The Electron application's context isolation was improperly configured, exposing the IPC renderer to the DOM. This architectural flaw allows JavaScript code running in the web context to invoke privileged system operations typically reserved for the main process.

Attack Vector

The attack is network-based and requires user interaction. An attacker can exploit this vulnerability by:

1. Crafting a malicious Mermaid diagram containing embedded JavaScript payloads
2. Delivering this content to a victim through chat messages, shared documents, or any interface that renders Mermaid diagrams
3. When the victim views the malicious diagram, the JavaScript executes in the renderer context
4. The malicious script leverages the exposed IPC interface to invoke system commands
5. Arbitrary code execution occurs with the privileges of the DeepChat application

The vulnerability mechanism involves the Mermaid diagram parser accepting and executing JavaScript within diagram definitions. The exposed window.electron or similar IPC bridge objects then enable the attacker's script to call native system functions. For detailed technical information, refer to the GitHub Security Advisory.

Detection Methods for CVE-2025-67744

Indicators of Compromise

• Unusual Mermaid diagram content containing JavaScript code patterns such as <script>, event handlers, or IPC invocations
• Unexpected child processes spawned by the DeepChat application
• System command execution originating from Electron renderer processes
• Suspicious IPC calls attempting to access system resources or execute commands

Detection Strategies

• Monitor DeepChat application logs for rendering errors or unusual JavaScript execution patterns
• Implement endpoint detection for process injection or child process spawning from Electron applications
• Deploy network monitoring to identify suspicious content being delivered to DeepChat instances
• Use application sandboxing solutions to detect breakout attempts from Electron renderer contexts

Monitoring Recommendations

• Enable verbose logging in DeepChat to capture diagram rendering activities
• Configure SIEM rules to alert on process chains involving DeepChat spawning unexpected executables
• Monitor for file system modifications initiated by the DeepChat process outside normal operational directories
• Implement behavioral analysis to detect Electron IPC abuse patterns

How to Mitigate CVE-2025-67744

Immediate Actions Required

• Upgrade DeepChat to version 0.5.3 or later immediately
• If immediate upgrade is not possible, consider temporarily disabling Mermaid diagram rendering functionality
• Review system logs for any indicators of prior exploitation
• Isolate affected DeepChat installations until patching is complete

Patch Information

ThinkInAI has released version 0.5.3 of DeepChat which addresses this vulnerability. The patch implements proper Mermaid configuration with content sanitization and corrects the Electron IPC exposure. The fix can be reviewed in the GitHub commit b179d97921af04a0ae1ae68757338dd8b8cbefe7. Organizations should prioritize this update given the critical severity and potential for full system compromise. Additional details are available in the GitHub Security Advisory.

Workarounds

• Disable or restrict Mermaid diagram rendering until the patch can be applied
• Implement network-level filtering to block potentially malicious diagram content
• Run DeepChat in a sandboxed environment or container to limit the impact of potential exploitation
• Restrict DeepChat to trusted content sources only until the upgrade is complete

# Verification command to check DeepChat version
deepchat --version
# Ensure output shows version 0.5.3 or higher