UPDATE: Apparently Stone was stabbed in the midst of a street fight outside some popular bars at 12:45AM. That would make it unlikely that this was a jihad attack.
It has not yet been announced whether or not his attacker was a revenge-seeking Muslim who was angry over the prevention of the jihad mass murder attack on the train. More details as they break.
“Hero in French train attack reportedly stabbed,” by Caitlin Dickson, Yahoo News, October 8, 2015:
According to CBS News U.S. Airman Spencer Stone, who helped foil a terror attack on a French train this summer, is in critical condition after being “repeatedly stabbed.” CBS is reporting that the stabbing took place last night, but further details about the incident are not yet available.