For diodes in series, the forward current is for the lowest rated current diode. If the diodes have the same forward current then it is that rating.
When diodes are placed in series the current rating does not change, but the PIV does, and it = the addition of the individual diode PIV. When diodes are placed in series to increase the PIV rating it is highly recommended to parallel each diode with a high value of resistor to equalize the PIV across each diode.