Input validation vulnerability in Responsive Pricing Table 5.1.8

The Responsive Pricing Table plugin for WordPress is vulnerable to a type of attack known as Stored Cross-Site Scripting. This kind of attack can be used by malicious people with access to the WordPress administrator settings, to inject harmful code into pages. This code will be executed whenever someone visits the injected page, and can harm both the user viewing the page and the website itself. This issue affects all versions of the plugin up to 5.1.8, and only affects multi-site installations and installations where unfiltered_html has been disabled.