Russia gained 117.38 square kilometers (45.32 square miles) in Ukraine through October 2026, while recording a second straight month of net losses, the Institute for the Study of War (ISW) said. The institute based its 10-month tally on its review of open-source evidence.
For October, ISW estimated that Russian forces seized or consolidated 139.85 square kilometers but lost 167.14 square kilometers, for a net decline of 27.29 square kilometers. When it included areas where Russian forces had entered without establishing control, the institute put the month’s net loss at 76.38 square kilometers.
ISW said some of Russia’s October losses were in Donetsk Oblast, where Moscow is pursuing a campaign to capture the region’s fortified cities, known as the Fortress Belt.
Ukraine’s Third Army Corps says its four-stage Operation Vivaldi restored 277 square kilometers and 16 settlements to Ukrainian control near Lyman.
ISW assessed that the operation defeated Russia’s planned northern pincer of an effort to encircle the Fortress Belt. The institute said Russia had not formally abandoned that campaign plan and reported no indication that Moscow had changed it to account for the setback near Lyman.
The Third Army Corps carried out a prolonged campaign of intermediate-range strikes against Russian logistics, fuel supplies and drone operators, ISW said. The institute linked those strikes to conditions that supported later Ukrainian advances.
In its Nov. 1 assessment, ISW said Russian forces attacked toward Lyman and Dobropillia on Oct. 31 and Nov. 1 without advancing. Ukrainian forces counterattacked near both areas.
