WordPress just forced an update to the Jetpack plugin on my site and emailed me about it, which was a strange first since I have auto-updates turned off. Looking at the changelog, it's because prior to this 13.9.1 update, any logged in user was able to view form submissions, no matter which user roll they had. So if a site allowed account creation of any kind, like for subscribers or commenters, all those users could view form submissions. Now, only users with permission to edit pages can view form submissions.
Anyone with private information submitted through forms and open user account creation should be aware that your data could have been accessed.