Input validation vulnerability in WordPress File Upload 4.16.3

The WordPress File Upload plugin for WordPress is vulnerable to a security issue called Cross-Site Scripting. This issue exists in versions of the plugin up to and including version 4.16.3. It occurs because the plugin does not take enough steps to stop people from adding malicious code to the plugin. If this code is added, it can run in the victim’s browser and allow the attacker to do things like steal their information or hijack their account.