The 32-year-old was expected to return to Spain this month after failing to make his mark in Wales.
The striker joined Cardiff last year, but failed to find the back of the net in only five appearances in the first half of the season.
The Bluebirds announced the transfer on their Twitter account by stating: "#CardiffCity can confirm that striker Javi Guerra has today joined @MalagaCF on an international loan deal until June 30 '15. #GoodLuckJavi."
Guerra moved to Cardiff from Real Valladolid, where he spent four years of his playing career.