See how meow gallery compares to other vendors in security performance
The Meow Gallery WordPress plugin before 5.5.2 does not escape an attachment's alt text before outputting it into an attribute of the link it builds for linked galleries, allowing users with the Author role or above to store a JavaScript payload that executes in the browser of any visitor (including administrators) who views a post containing such a gallery.
The Meow Gallery WordPress plugin before 5.5.5 does not properly sanitize a user-supplied value before concatenating it into a shortcode string that it passes to the WordPress shortcode parser on a publicly reachable endpoint, allowing unauthenticated users to execute arbitrary registered shortcodes and disclose non-public gallery content.