The Serious Slider WordPress plugin before 1.2.7 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.
Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in Cryout Creations Serious Slider allows Stored XSS.This issue affects Serious Slider: from n/a through 1.2.4.