Blatant lie, no. Misleading, for sure. She should have been more specific.

From Politfact - quoting the Defense Dept:
A Defense Department spokesperson told PolitiFact that the U.S. is neither engaged in a war, nor has service members fighting in active war zones anywhere in the world.

"An aspect of military service includes serving in locations where hostile actions may occur," the Defense Department official said in a statement to PolitiFact. "Those locations are designated by executive order and/or the Secretary of Defense. However, it’s important to note that just because a service member is in one of these locations does not mean they are engaged in war."

But Harris’ inclusion of "combat zone" in that statement is misleading and experts said it significantly underplays the broader landscape of active duty military service abroad.