Ukraine's Third Army Corps has driven a sustained counteroffensive, Operation Vivaldi, across multiple phases through October 2026, reclaiming over 270 square kilometers and more than a dozen settlements north and east of Lyman while inflicting thousands of Russian casualties and forcing redeployments from the Kupiansk axis. Russian units from the 20th and 25th Armies, which had previously advanced toward the city and attempted limited infiltrations, were pushed back across the Chornyi Zherebets River and lost key logistics points, reversing prior gains aimed at encircling the Sloviansk-Kramatorsk defensive belt. Russian forces continue localized attacks toward Lyman and nearby villages, yet Ukrainian positions in the city itself remain intact amid ongoing artillery, drone, and ground clashes. Both sides are repositioning for further fighting, with Ukrainian reinforcements stabilizing the sector and Russian command adjusting broader Donbas plans.