Vagner Love loaned to Palmeiras
Vagner, 25, who started his career with Palmeiras, has been CSKA's top forward since joining for $8 million in 2004, helping the army club to two league titles and the UEFA Cup in 2005.
Palmeiras announced the deal on their official website with a CSKA spokesman adding that Vagner had left Russia for "family reasons."
He was the Russian league's top scorer last year but has not shown the same form this season.
Brazilian media said Vagner wanted to return to his native country to have a better chance of making Brazil coach Dunga's squad should they reach next year's World Cup in South Africa.
He has 18 caps but has not played for Brazil since 2007.