It will be a third loan period away from the Cherries for the 21-year-old, who enjoyed a fruitful loan spell with Havant & Waterlooville in 2018-19, making 34 appearances and scoring four goals in the National League.
Cordner spent the first half of last season on loan to Ebbsfleet United at the same level, making a further 20 appearances in the National League and three in the FA Cup.
He signed his first professional deal with Bournemouth at the end of the 2016/17 season. The central defender then joined the club's under-21 squad after successfully graduating from the youth team.
The move to the Sands Venue Stadium sees him link up with Cherries team-mate Frank Vincent, who is also on loan with the Iron, and he will take the Number 26 shirt.
