On the night of the 21st of July 2018 after the light show "Rêve de Couleurs," on the facade of the cathedral, a drunk individual shouted "Allahu Akbar! Long live Daech! I will butcher you!" at all the people he met in front of the cathedral. He further threatened: "I'm going to attack! I'm going to blow up the cathedral!" A passerby who tried to interfere was slapped. The perpetrator has been identified as 19-year-old Tony Brébant from Reims who recently converted to Islam. He was sentenced to fourteen months in prison on the 28th of August 2018.
Sources: L'Union here and here, Breizh-Info and christianophobie.fr