Kumara was fined 25 per cent of his match fee while Das was fined 15 per cent of his, with both players also getting one demerit point.
The two players were involved in an altercation after Kumara dismissed Das in the fifth over during a Group 1 game in Sharjah on Sunday.
The ICC said Kumara walked towards Das “using actions and words which provoked an aggressive reaction from the batter.”
Das also reacted aggressively and in a manner contrary to the spirit of cricket.
Sri Lanka won the match by five wickets.