"As usual, we recommend updating as soon as you can, for the fixes much more than the features.Apple iOS 9 is out – with a LOT of security holes patched | Naked Security
And when you do the update, take the opportunity to review your security settings in general.
For example, we made sure that location services were turned off, as we wanted; and that the auto-sync features of iCloud were disabled, especially the one that pushed photos and screenshots to the cloud automatically.
Those may not be your preferences, of course, but do take the opportunity to check that your settings reflect your choices, and that you don't finish the update with a bunch of unwanted security changes."
Friday, September 18, 2015
Apple iOS 9 is out – with a LOT of security holes patched | Naked Security
Check the full post for an overview of security-related updates