An Arduino should not be used as a power supply for a servo. The 5V pin is connected to the the 5V supply of the USB connector, OR to the output of a step-down buck regulator converting the DC barrel jack to 5V.
None should be considered "high current" for servo or motor use.
Most PC USB ports will max out at 500mA current output unless the device connected asks for more from the PC. The Arduino does not.
The buck-converter controller chip is a LM2434, whose datasheet specifies 1A maximum output current.
Driving motors or servos will draw enough current, intermittently, to overload either of those and will likely cause the Arduino to reset.
If you need to power a motor-type device, power it separately from the control signals. Power should go from the source to the motor, and the control signal from the Arduino to the servo, making sure to connect the ground wires of all to each other (motor, Arduino, power source).