B767 Captain reported executing a go-around from a low altitude on final approach after encountering jet blast from a taxiing aircraft.

Narrative

From 500' on visual approach to flare for landing RWY XXR there was no turbulence and light wind only. During flare slightly below 30' we experienced what I would describe as severe wake turbulence. The aircraft snapped violently left wing low; the FO (PF) instantly applied almost full right aileron to bring the aircraft to wings level. Instantly the aircraft violently snapped right wing low then left wing low and sink rate increased rapidly. While this was occurring I (PM) called for a go-around while the FO (PF) was instinctively adding power and initiating a go-around. With go-around power coming in the aircraft touched down on main gear; wings level; at a normal sink rate momentarily before climbing for the go-around. We leveled at 3000' and were vectored for a visual approach to RWY XY.Tower asked the reason for the go-around. After being handed off to approach; they too asked the reason for the go-around. We stated severe turbulence during the flare. After landing; Tower asked us to call them which we did after shutdown. Tower wanted to clarify information for their report and informed us that we had landed 4.5 miles in trail of a B373-800 but did not think the 737 should have generated such strong wake turbulence. I agreed with tower that I did not believe the 737 created the wake turbulence we experienced. Tower then informed us that there was a 767 taking runway XXC from taxiway 1 at the time we were landing and thought it was possible that the jet blast from that aircraft caused the severe turbulence we experienced. I agreed that that is most likely what occurred. FO (PF) did a superb job of controlling the aircraft and applying go around power quickly. The aircraft did not sustain any damage and was not stressed more than ordinary during this event.The FO and I believe the heavy 767 taking runway XXC from taxiway 1 most likely generated jet blast which swept across the touchdown zone of runway XXR.Suggestion: Power setting awareness while taxiing and its effect on parallel runways.