The Post Grid, Post Carousel, & List Category Posts WordPress plugin before 2.4.19 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/19379f08-d667-4b1e-a774-0f4a17ad7bff