MySQL 5.7 Release Notes
This section describes general security issues to be aware of and what you can do to make your MySQL installation more secure against attack or misuse. For information specifically about the access control system that MySQL uses for setting up user accounts and checking database access, see Section 2.9, “Postinstallation Setup and Testing”.
For answers to some questions that are often asked about MySQL Server security issues, see Section A.9, “MySQL 5.7 FAQ: Security”.