The Page Builder: Live Composer WordPress plugin before 1.5.23 does not validate and escape some of its shortcode attributes before outputting them back in a page/post where the shortcode is embed, which could allow users with the contributor role and above to perform Stored Cross-Site Scripting attacks.
https://wpscan.com/vulnerability/79f011e4-3422-4307-8736-f27048796aae