The Logo Slider – Logo Carousel, Client Logo Slider & Brand Showcase for WordPress plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'lgx_tooltip_position' parameter in all versions up to, and including, 5.5 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.