Guys, relax… it's almost certainly people mis-reporting 2018.26 3bbd9fd. Tesla just pushed out another wave of that update to ~10-15% of the fleet today. That would be stupid if they were planning on another 26 point release the same day for S/X.
On EV-FW, you select your firmware version from a drop-down list. Once a single person fills out 26.3, everyone else will be tempted into selecting it because it looks similar to their version.