The Reviews Feed WordPress plugin before 2.6.5 does not neutralize WordPress shortcodes contained in third-party review content before rendering it through its dynamic block, allowing unauthenticated attackers to execute arbitrary shortcodes on pages that display the feed by planting a shortcode in a review on the connected source.
https://wpscan.com/vulnerability/7def5cf4-655d-424b-b1fc-eb333465434e/