Google Groups is a service from Google that provides discussion groups for people sharing common interests. By default, Google Groups are set to private; there have been a number of instances, however, where G Suite Administrators have accidentally shared sensitive information as a result of misconfigured Google Groups privacy settings. Google has published a G Suite update here.
According to a recent research by Kenna Security, thousands of organizations seem to be inadvertently leaking internal or customer information. Examples of real e-mails found during the research are past due invoices, password recovery information and GitHub credentials.
Read more about it here.