Dubajić was born in the village of Kistanje near Knin. When World War II broke out, he joined the partisan resistance movement, and advanced in ranks to the rank of major. At the end of the war, Dubajić was the commander of a mechanized squad of the 4th Army of Yugoslavia (the Croatian branch of the Yugoslav National Liberation Army, led by Lieutenant General Petar Drapšin). In the spring of 1945, they were stationed in the region of Kočevje in Slovenia, where they were reportedly involved in the events related to the Bleiburg repatriations