The Donation Block For PayPal WordPress plugin before 2.1.0 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.
https://wpscan.com/vulnerability/8c50321a-dba8-4379-9b9c-4c349e44b2ed