SHOW TABLES allows users with only GRANT OPTION privilege to read all table names in the database "mysql"

-- Login as ROOT user

CREATE USER regular;

GRANT GRANT OPTION ON *.* TO regular;

-- Login as regular user

SHOW TABLES FROM mysql;

/* Expected Behavior: ERROR 1044 (42000): Access denied for user 'regular'@'%' to database 'mysql'

Actual Behavior:

+---------------------------+

| Tables_in_mysql           |

+---------------------------+

| column_stats              |

| columns_priv              |

...

| user                      |

+---------------------------+

*/

-- Note: running the same commands in MySQL will get correct behavior:

-- ERROR 1044 (42000): Access denied for user 'regular'@'%' to database 'mysql'