Yes they are at risk. I don’t think we know yet if there will be a patch. For my iPad mini on iOS 15, I’ve turned off iMessage on it (it’s wifi only).

It seems to be a very critical flaw so I think there’s a good chance they will put out a security patch for iOS 15.

Apple, in particular, seems a favorite target of NSO. And Apple seems intent on winning their game of whack-a-mole. I would expect them to patch as far back as justifiable and feasible.

Maybe it will get it, I remember 2-3 years ago, they even updated all the way to the iPhone 4 for a security patch

Apple patches older releases for zero day bugs. If there is no patch, then usually it means the exploit doesn’t work on that older release.

https://www.macrumors.com/2023/09/11/apple-security-updates-older-operating-systems/

Does anyone know if ios 15 is even vulnerable? or was this an exploit introduced in 16? Given the lack of response on 15 I would assume its not.