Known Vulnerabilities in this plugin

I have a WordPress web site with the ActiveCampaign WordPress plugin and I am getting notifications of Cross Site Scripting (XSS) vulnerability. This means hackers can get into my site through this plugin. I have waited several days for ActiveCampaign to update the plugin but they have not. Patchstack flagged version 8.1.16. See their notice: https://patchstack.com/database/wordpress/plugin/activecampaign-subscription-forms/vulnerability/wordpress-activecampaign-plugin-8-1-16-cross-site-scripting-xss-vulnerability
Patchstack believes this plugin has been abandoned. Remove it to be safe.