WordPress Kupon premium theme <= 1.27 - Unauthenticated Reflected Cross-Site Scripting (XSS) vulnerability

Unauthenticated Reflected Cross-Site Scripting XSS vulnerability discovered by m0ze in WordPress Kupon premium theme versions = 1.27. Solution 9 June 2021 - Theme removed from the Themeforest repository. Unfortunately, no information about the patched version is available...