The MAX4291 is unity-gain stable for capacitive loads up to 100pF, so if your voltage follower is driving circuitry with an effective capacitance above 100pF you will experience some ringing on the output. You can mitigate this by adding a series resistor between the op-amp output and the circuitry to be driven, sometimes referred to as an isolation resistor. Please note that this may affect the voltage accuracy depending on the load to be driven, as it will form a resistive divider.