The TableOn – WordPress Posts Table Filterable plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'tableon_button' shortcode in all versions up to and including 1.0.4.4. This is due to insufficient input sanitization and output escaping on user-supplied shortcode attributes such as 'class', 'help_link', 'popup_title', and 'help_title'. The do_shortcode_button() function extracts these attributes without sanitization and passes them to TABLEON_HELPER::draw_html_item(), which concatenates attribute values into HTML using single quotes without escaping (line 29: $item .= " {$key}='{$value}'"). 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.