The soledad WordPress theme before 8.2.5 does not sanitise the {id,datafilter[type],...} parameters in its penci_more_slist_post_ajax AJAX action, leading to a Reflected Cross-Site Scripting (XSS) vulnerability.
https://wpscan.com/vulnerability/7a244fb1-fa0b-4294-9b51-588bf5d673a2