Description
The shop page https://store.arduino.cc/products/arduino-leonardo-with-headers has a table value DC Current per I/O Pin with 40 mA. This is the absolute maximum in the manufactuer's datasheet for the microcontroller. The text in Input and Output section matches this value, see below.
Each of the 20 digital i/o pins on the Leonardo can be used as an input or output, usingpinMode(), digitalWrite(), and digitalRead() functions. They operate at 5 volts. Each pin can provide or receive a maximum of 40 mA and has an internal pull-up resistor (disconnected by default) of 20-50 kOhms. In addition, some pins have specialized functions:
Under Tech Specs tab in https://docs.arduino.cc/hardware/leonardo/#tech-specs the DC Current per I/O Pin in the table says 10 mA
(I note these two values do not match the 20mA value recommended for the Arduino UNO R3 using a very similar microcontroller.)