The Post Grid, Posts Slider, Posts Carousel, Post Filter, Post Masonry WordPress plugin before 2.2.93 does not validate and escape some of its block options before outputting them back in a page/post where the block is embed, which could allow users with the contributor role and above to perform Stored Cross-Site Scripting attacks.
The Post Grid and Gutenberg Blocks – ComboBlocks plugin for WordPress is vulnerable to Sensitive Information Exposure in all versions up to, and including, 2.3.6 via the /wp-json/post-grid/v2/get_users REST API This makes it possible for unauthenticated attackers to extract sensitive data including including emails and other user data.