Input validation vulnerability in Collapse-O-Matic 1.8.5.8

The Collapse-O-Matic plugin for WordPress has a security issue that can be exploited by hackers. This vulnerability allows them to insert harmful code into web pages, which will run when someone views the page. It affects all versions of the plugin up to 1.8.5.7 and is caused by not properly filtering and securing user input. Only users with contributor-level access or higher can perform this attack.