The two men each reportedly paid an amount that ran into the millions of dollars for the software, but the exact figure is not known.
The revelation has sparked questions about why the two men purchased the hacking software independently of each other, despite being leaders in a country with a joint federal military, police and security forces.
It has been speculated that the royals were using the Israeli hacking software to spy on their political rivals within the UAE.
Makhtoum has already been accused of using the hacking tool for his own personal benefit.
Last month a UK court ruled that Makhtoum was guilty of using the Pegasus hacking software to spy on his estranged wife, her friends, and members of her legal council, during the couple’s custody battle over their two children in London.
The information regarding the hack of Princess Haya bint Hussein was revealed by NSO themselves, who have engaged in a fierce campaign of damage limitation following damning revelations that Pegasus has been used to spy on human rights activists, political opponents, journalists, and even heads of state.
Following the revelations regarding the Dubai ruler and his wife, the NSO group announced in October that they had ended their contract with the UAE.