The Landing Page Builder WordPress plugin before 1.4.9.9 does not validate and escape some of its shortcode attributes before outputting them back in the page, which could allow users with a role as low as contributor to perform Stored Cross-Site Scripting attacks which could be used against high privilege users such as admins.
https://wpscan.com/vulnerability/04d7cd44-9e18-42b9-9f79-cc9cd6980526