Following the outbreak of German invasion of Soviet Union in June 1941, Hibner joined the Red Army. On 29 August 1943, he was assigned to the 1st Tadeusz Kościuszko Infantry Division, where he was appointed as the deputy commander of the regiment's political affairs. He distinguished himself during the Battle of Lenino in 1943, when at the critical moment of the battle, he replaced the deceased battalion commander and despite receiving two severe wounds, he led the battalion. He was erroneously presumed dead and was posthumously nominated for the title of Hero of the Soviet Union, when in fact he was being treated at a military hospital. By the decree of the Presidium of the Supreme Soviet of the USSR of 11 November 1943, he was awarded the title of Hero of Soviet Union, along with an award of the Order of Lenin. After recovery, he was promoted to lieutenant colonel and appointed as regiment commander within the 2nd Polish Army.