Input validation vulnerability in Mmm Simple File List 2.3

The Mmm Simple File List plugin for WordPress is vulnerable to a type of cyberattack called Stored Cross-Site Scripting. This type of attack can be used to inject malicious code into pages on a website. All versions of the plugin, up to and including version 2.3, are vulnerable due to a lack of proper input sanitization and output escaping. If an attacker with contributor-level or higher permissions is able to exploit this vulnerability, they could use it to inject scripts into pages that would be executed whenever someone visits those pages.