The Iron extended their unbeaten run to 18 games with a second-half recovery at Rodney Parade. David Syers looked to have sent them above leaders Chesterfield when he scored seven minutes from time. However, Zebroski pounced in added time with his ninth goal of the season to snatch a deserved draw.
The Exiles feared they had paid a heavy price for failing to make the most of their first-half dominance.
Ryan Burge had a strong penalty claim waved away, saw his driving effort palmed away by Sam Slocombe and then shot over the bar from Lee Minshull's cross.
Niall Canavan was booked for a foul on Zebroski and, from the resulting free-kick, Minshull headed in from close range on 25 minutes.
The visitors dusted themselves down and struck back in the second half. Marcus Williams and Eddie Nolan combined for Paddy Madden to side-foot home on the hour.
Hakeeb Adelakun then set up Syers on 83 minutes to give Scunthorpe the lead yet Newport rallied with Zebroski's late goal.