Overview

This repository contains a Proof-of-Concept (POC) script for CVE-2026-39987, a pre-authentication Remote Code Execution (RCE) vulnerability in Marimo. The exploit leverages a WebSocket endpoint to execute arbitrary commands on the target system.

Vulnerability Details

• CVE ID: CVE-2026-39987
• Affected Component: Terminal WebSocket endpoint (/terminal/ws)
• Impact: Unauthorized remote code execution without authentication
• Affected Versions: <= 0.20.4

Advisory Reference

• GHSA-2679-6mx9-h9xc

Prerequisites

• Python 3.x
• Required packages:

  pip install websocket-client
  

Usage

python exploit.py -u <TARGET_URL> [-c ""]
python exploit.py -u http://example.com:2718 -c "cat /etc/passwd"

-u, --url: Target URL (e.g., http://localhost:2718)
-c --command: Command to execute (defaults to id && whoami && hostname)
-h, --help

Disclaimer

This script is intended for educational and research purposes only.
Use responsibly and only against systems you own or have explicit permission to test.
Misuse of this tool may result in unintended consequences and potential security risks.
By using this script, you acknowledge that you are solely responsible for any actions taken.