Leicester had been docked points after being found to have breached EFL profit and sustainability (P&S) rules for the 2023/24 season.
The commission determined the club breached the relevant P&S threshold by £20.8million over the three-year assessment period ending 2023/24.
The Foxes were also found to have breached Premier League rules in failing to provide their annual accounts to the league when requested.
They appealed the decision, but have been told the six-point deduction has been upheld, leaving them at risk of relegation to League One.
Gary Rowett’s side are 22nd in the Championship, one point adrift of Portsmouth in safety, with just five league matches left to play this season.