The Media Library Assistant plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'mla_gallery' shortcode in versions up to and including 3.35. This is due to insufficient input sanitization and output escaping on the mla_link_href parameter when mla_output is set to 'paginate_links', where the _paginate_links() function processes the value through mla_process_shortcode_parameter() and _replace_query_parameter() without proper URL escaping, then outputs it directly in href attributes without applying esc_url(). 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.