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.
https://wpscan.com/vulnerability/cfd6db83-5e7f-4631-87c3-fdcd4c64c4fe/