Dangers to allowing Access-Control-Allow-Origin: * for Feeds only?

I want to use a function like this to allow access to the feeds from a variety of services but my knowledge of the security implications is limited. I think I’m being safe by limiting the access to feeds.

What are the dangers (if any) I’m creating if I do this?

add_action( 'pre_get_posts', 'add_header_origin' );

function add_header_origin() {
    if (is_feed()){
        header( 'Access-Control-Allow-Origin: *' );
    }
}