The Post Grid, Slider & Carousel Ultimate – with Shortcode, Gutenberg Block & Elementor Widget plugin for WordPress is vulnerable to PHP Object Injection in all versions up to, and including, 1.6.7 via deserialization of untrusted input in the outpost_shortcode_metabox_markup function. This makes it possible for authenticated attackers, with contributor-level access and above, to inject a PHP Object. If a POP chain is present via an additional plugin or theme installed on the target system, it could allow the attacker to delete arbitrary files, retrieve sensitive data, or execute code.

The Post Category Image With Grid and Slider WordPress plugin before 1.4.8 does not validate and escape some of its shortcode attributes before outputting them back in the page, which could allow users with a role as low as contributor to perform Stored Cross-Site Scripting attacks which could be used against high privilege users such as admins.

The Post Grid, Slider & Carousel Ultimate WordPress plugin before 1.5.0 does not sanitise and escape the Header Title, which could allow high privilege users to perform Cross-Site Scripting attacks even when the unfiltered_html capability is disallowed.