A flaw in the permission enforcement of several Apple operating systems allows an application to write to a file that it should only be able to read. The vulnerability is an access control weakness that can be leveraged to tamper with protected files, potentially compromising the integrity of the operating system or installed applications.

The issue appears in iOS, iPadOS, macOS, tvOS, and visionOS. It was fixed in iOS 27, iPadOS 27, macOS Golden Gate 27 and Sequoia 15.8, macOS Tahoe 26.7, tvOS 27, and visionOS 27. Devices running any of these OS families before those releases may be susceptible.

The vulnerability is defined with a CVSS score of 5.5, indicating medium severity. This score reflects the potential for an application to overwrite files it should only read, potentially disrupting application functionality or modifying system configuration. Because the flaw requires the presence of a malicious or compromised application on the device, it is a local privilege escalation vector, but it can affect multiple files if the application has broad file‑system permissions. The EPSS score of <1% suggests a low probability of exploitation in the wild, and the vulnerability is currently not listed in CISA KEV. A device running any pre‑27 (iOS/iPadOS), pre‑26.7 (macOS Tahoe), or earlier tvOS/visionOS versions remains vulnerable.