The Google Tag Manager for WordPress (GTM4WP) plugin is vulnerable to Stored Cross-Site Scripting due to insufficient escaping via the `gtm4wp-options[scroller-contentid]` parameter found in the `~/public/frontend.php` file which allowed attackers with administrative user access to inject arbitrary web scripts, in versions up to and including 1.15.1. This affects multi-site installations where unfiltered_html is disabled for administrators, and sites where unfiltered_html is disabled.
https://www.wordfence.com/vulnerability-advisories/#CVE-2022-1961
https://wordpress.org/plugins/duracelltomi-google-tag-manager/#developers
https://gist.github.com/Xib3rR4dAr/02a21cd0ea0b7bf586131c5eebb69f1d