security vulnerability

I got a security warning for this plug-in:

The Shariff Wrapper plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin’s ‘shariff’ shortcode in all versions up to, and including, 4.6.13 due to insufficient input sanitization and output escaping on user supplied attributes such as ‘borderradius’ and ‘timestamp’. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

https://www.wordfence.com/threat-intel/vulnerabilities/wordpress-plugins/shariff/shariff-wrapper-4613-authenticated-contributor-stored-cross-site-scripting-via-shortcode

The page I need help with: [log in to see the link]