This report says they discovered this in March.

The NY Times [1] just reported that "Apple’s security team has been working around the clock to develop a fix since Tuesday, after researchers at Citizen Lab, a cybersecurity watchdog organization at the University of Toronto, discovered that a Saudi activist’s iPhone had been infected with spyware from NSO Group."

What took so long? Did Apple not know about this in March or was someone sitting on it for 6 months?

[1] https://www.nytimes.com/2021/09/13/technology/apple-software...