The Logo Carousel WordPress plugin before 3.4.2 allows users with a role as low as Contributor to duplicate and view arbitrary private posts made by other users via the Carousel Duplication feature
The Logo Carousel WordPress plugin before 3.4.2 does not validate and escape the "Logo Margin" carousel option, which could allow users with a role as low as Contributor to perform Stored Cross-Site Scripting attacks
The Client Logo Carousel WordPress plugin through 3.0.0 does not validate and escape some of its shortcode attributes before outputting them back in a page/post where the shortcode is embed, which could allow users with the contributor role and above to perform Stored Cross-Site Scripting attacks.