MiniGal Nano version 0.3.5 and prior contain a reflected cross-site scripting (XSS) vulnerability in index.php via the dir parameter. The application constructs $currentdir from user-controlled input and embeds it into an error message without output encoding, allowing an attacker to supply HTML/JavaScript that is reflected in the response. Successful exploitation can lead to execution of arbitrary script in a victim's browser in the context of the vulnerable application.