Gary Lane, 52, of Fairfax Road in Kidlington, Oxfordshire, attacked the boys between January and November 2015.
He admitted two counts of raping a child under 13, sexually assaulting a child under 13, and causing or inciting a child to engage in sexual activity.
Judge Patrick Eccles, sentencing Lane at Oxford Crown Court, described him as an "unscrupulous paedophile".
The boys were not members of any scout group at the time of the offences.
Judge Eccles told Lane: "You are an unscrupulous paedophile who has shown a depraved course of conduct.
"You have shown no sense of remorse... there is something wrong with your sexual thinking."
Rhys Bevan, of Thames Valley Police's child abuse investigation unit, said Lane was "where he belongs".
He added: "What Lane has put the victims and their families and loved-ones through is horrendous.
"Lane failed to turn up for court twice in 2016, fleeing once to Scotland, which caused unnecessary stress for all involved."
A "depraved" former scout leader has been jailed for 16 years for raping two boys aged eight and 10-years-old.