WooCommerce released a security update for all versions since 3.5 for a found vulnerability in the PayPal Standard payment gateway.
WooCommerce recommends switching to the PayPal Payments plugin instead of the PayPal Standard which is no longer developed. All users using WooCommerce versions below 3.5 need to disable the PayPal Standard and migrate to PayPal Payments plugin
Remember to create a backup before updating your site.
