Magento released security updates for Magento version 2.1 and 2.0. These updates are recommend to install as soon as possible. The 15 security enhancements are fixing critical security issues, like the remote code execution for authenticated admin users, access control bypass, and cross-site request forgery issues.
Magento 2.1.7 and 2.0.14 contain also support for MasterCard BIN number expansion and a reversion of the changes to image resizing that has been introduced in 2.1.6, because of unanticipated problems.
For more details visit the official release notes (2.1.7, 2.0.14).
