The Adwised Web Push Notification WordPress plugin through 2.5.7 does not perform any capability or nonce check before allowing an authenticated user to overwrite its site-wide configuration, and does not escape those configuration values before printing them inside an inline script block on every front-end page, allowing any authenticated user, such as a subscriber, to perform Stored Cross-Site Scripting attacks against every visitor, including administrators.
https://wpscan.com/vulnerability/862d0ae8-eb6a-4a39-a941-597892c40eb0/