The Easy Accordion WordPress plugin before 2.2.0 does not validate and escape some of its shortcode attributes before outputting them back in the page, which could allow users with a role as low as contributor to perform Stored Cross-Site Scripting attacks which could be used against high privilege users such as admins.
https://wpscan.com/vulnerability/6130958f-f549-4885-adb1-093aa025920e