Apple CloudKit Entitlement Check Vulnerability Allowing User Fingerprinting

A vulnerability exists in the CloudKit framework of various Apple operating systems, including visionOS 26, tvOS 26, iOS 26, iPadOS 26, and watchOS 26. This vulnerability allows apps to fingerprint users by exploiting insufficient entitlement checks. The issue has been addressed in the respective updates for each operating system.

Impact

Exploitation of this vulnerability could lead to unauthorized user fingerprinting, allowing apps to track or identify users based on their device usage or characteristics.