The WP ULike plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the [wp_ulike_likers_box] shortcode template attribute in all versions up to, and including, 5.0.1. This is due to the use of html_entity_decode() on shortcode attributes without subsequent output sanitization, which effectively bypasses WordPress's wp_kses_post() content filtering. 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 post must have at least one like for the XSS to render.