Trying to discover a hidden 4-digit number I got the following hints:

GUESS RESULT
+---------+-------+
| 1 2 3 4  | B B   |
+---------+-------+
| 5 6 7 8  | B B   |
+---------+-------+
| 8 6 9 0  | B R   |
+---------+-------+

B- One of the digits of this guess exists in the hidden number in THE SAME position.
R- One of the digits of this guess exists in the hidden number in ANOTHER position.

What is the number?