High · published October 29, 2025
⚠️ A command-injection vulnerability lurking in FastMCP may allow attackers to execute arbitrary OS commands just by manipulating the server_name field! 🚨 Think of it like a mischievous guest at a restaurant who tweaks their order just enough to get the chef to whip up something entirely different—except in this case, the chef is your server, and they might just cook up a security nightmare! An attacker with the right influence could run any command on your Windows hosts that run FastMCP, potentially leading to unauthorized access, data manipulation, or even full server control. While it’s not currently exploited, the risks can escalate quickly if left unaddressed!
Think of it like a mischievous guest at a restaurant who tweaks their order just enough to get the chef to whip up something entirely different—except in this case, the chef is your server, and they might just cook up a security nightmare! This command-injection vulnerability in FastMCP allows an attacker to inject and execute arbitrary commands on Windows systems by manipulating the server_name parameter during the installation process.
An attacker with the right influence could run any command on your Windows hosts that run FastMCP, potentially leading to unauthorized access, data manipulation, or even full server control. While it’s not currently exploited, the risks can escalate quickly if left unaddressed! Upgrade FastMCP to version 2.13.0 or later immediately to patch this vulnerability. Additionally, review your application's input validation measures to mitigate similar risks in the future. You've got this! Patch up and keep your systems secure! 🛡️
| Product | Versions | Fixed in |
|---|---|---|
| jlowin/fastmcp | < 2.13.0 | 2.13.0 |