The Custom Content Shortcode WordPress plugin through 4.0.2 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/5cafbba6-478f-4f5d-a2d4-60c6a22f2f1e