The Smart Email Alerts WordPress plugin is vulnerable to Reflected Cross-Site Scripting via the api_key in the ~/views/settings.php file which allows attackers to inject arbitrary web scripts, in versions up to and including 1.0.10.
https://www.wordfence.com/vulnerability-advisories/#CVE-2021-34642
https://plugins.trac.wordpress.org/browser/smart-email-alerts/trunk/views/settings.php#L38