It is reported that we are talking about flight S7636 of Globus Airlines from the Italian city of Bari to Moscow. The FlightRadar24 website shows that the Boeing 737-800 changed the route and the aircraft flew over the territory of Ukraine for about half an hour. During the flight, the pilot contacted the Ukrainian side to obtain permission to use the country's airspace to avoid falling into a powerful thunderstorm front.
Recall that Ukraine banned flights of Russian aircraft on October 25, 2015. The airlines Aeroflot, Transaero, Yakutia, and S7, which had previously flown to Crimea, were blacklisted. Russia took retaliatory measures and, in turn, closed the sky for Ukrainian air carriers.