A flaw in Xbox Live has allowed hackers to find out anyone’s email address that was used for an Xbox gamertag. An anonymous hacker told Motherboard last week that they were able to discover the email addresses of anyone who had registered for an Xbox gamertag.
Email addresses are linked to the gamertags by default, but this information is private. Motherboard verified the existence of the vulnerability by providing the hacker with gamertags. The hacker then sent them back the email addresses that they had used to register the accounts within a matter of seconds.