The Smart Slider 3 WordPress plugin before 3.5.1.14 does not properly 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/3fe712bc-ce7f-4b30-9fc7-1ff15aa5b6ce