We wouldn't call it a catfight, but let's call it an episode of two people not getting along well with each-other. It happened when Katrina Kaif was new to the industry and Salman Khan was taking keen interest in her career and her personal life. Salman Khan's family member (back then) Malaika Arora, apparently, was not on great terms with Katrina.
It happened at a party where both Malaika and Katrina were present. Salman Khan's sister Alvira was also there. As per a report in Indiatimes, Katrina apparently made fun of Malaika's fashion label and even called it 'copied'. This obviously didn't go down well with Malaika who got into an argument with Alvira over why Katrina was even invited to the party in the first place.
The background
A Khaleejtimes report had stated that even when Salman was dating Katrina and the entire Khan-daan had accepted her with open arms, it was Malaika who didn't approve of her. The two have always shared cold vibe and it dates back to their modelling days.
Khan family's perspective
Malaika was apparently considered her a competition and didn't appreciate the family loving her so much. "From being a model she has successfully transitioned to become one of the top paid actresses in Bollywood. Malaika is also miffed about the fact that despite not being married to Salman, Katrina gets the same amount of respect, even though she has been stringing along Salman for ages. Salman has always been the favourite son of his parents and because of that Katrina was easily accepted into the family. Though Salim Khan is hurt that she is not ready to make any commitments, he still likes her because she has brought a certain balance into Salman's life. The Khan family is currently torn between two parties with the two daughters-in-law on one side and Katrina and Salman's sisters on the other," the report further stated.