Apple today released MacBook Pro Flash Storage Firmware Update 1.0 for the 2015 MacBook Pro, which fixes a storage firmware issue that could cause data corruption in rare cases.
Apple recommends that all customers who have a mid-2015 MacBook Pro download and install the update. It can be acquired from the Mac App Store on affected machines or directly from Apple's support site.
The mid-2015 MacBook Pro includes all 15-inch Retina MacBook Pro models that were released in May of this year. As MacRumors readers have pointed out, the 13-inch Retina MacBook Pro released in March is an "early-2015" model.