Ex-NBA star Sebastian Telfair has been convicted of possessing a firearm ... and could be sentenced to 15 years in prison.
Telfair -- a 33-year old former high school phenom who spent 12 season in the NBA -- was busted back in June 2017 in Brooklyn .... after cops found several weapons during a traffic stop.
Officials say Telfair -- who played with the Trail Blazers, Celtics, Clippers and Timberwolves, to name a few -- had 3 pistols and what appeared to be a semi-automatic rifle. Cops say he was also carrying a ton of ammo and a bulletproof vest .