Fiji were reduced to 14 men for the second half after Kuruvoli was sent off following a review for striking prop Ellis Genge in the chest.
"The disciplinary committee determined that the act merited a mid-range entry point of eight weeks/matches," organisers said in a statement on Thursday.
"In light of Kuruvoli accepting he committed an act of foul play as well as mitigating factors such as his disciplinary record, conduct, and remorse, the committee applied the full 50% reduction in sanction."
Kuruvoli will also miss three games for French club RC Vannes in September as part of the suspension.
Fiji are bottom of the Southern Hemisphere standings in the Nations Championship after starting their campaign with losses to England and Wales.
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