Apple releases emergency security updates to block Pegasus spyware exploiting iOS vulnerabilities

Spyware exploit discovered by Citizen Lab allowed infection of iPhones without user interaction.
Updates patch vulnerabilities in ImageIO and Apple Wallet app used to deliver Pegasus.
All iPhone, iPad, Apple Watch and Mac users advised to install updates immediately.
Pegasus spyware developed by NSO Group and sold to government agencies.
Lockdown Mode can help defend against similar exploits.