The Live Composer – Free WordPress Website Builder plugin for WordPress is vulnerable to Stored Cross-Site Scripting via dslc_module_testimonials_output Shortcode in all versions up to, and including, 2.1.19 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The injected payload survives save-time wp_kses_post filtering because KSES treats shortcode delimiters as opaque, and the unescaped fields — including main_heading_title, view_all_link, main_heading_link_title, and main_filter_title_all — are only rendered when do_shortcode() executes at page-view time.