Kernel Memory OOB Write in Apple OS (iOS <26.7, macOS <15.8)
CVE-2026-84523 Published on September 14, 2026

An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in iOS 26.7 and iPadOS 26.7, iOS 27 and iPadOS 27, macOS Golden Gate 27, macOS Sequoia 15.8, macOS Tahoe 26.7, tvOS 27, visionOS 27, watchOS 27. An app may be able to cause unexpected system termination or write kernel memory.

NVD

Vulnerability Analysis

CVE-2026-84523 can be exploited with local system access, and requires small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.

Attack Vector:

LOCAL

Attack Complexity:

LOW

Privileges Required:

LOW

User Interaction:

NONE

Scope:

UNCHANGED

Confidentiality Impact:

NONE

Integrity Impact:

NONE

Availability Impact:

HIGH

Weakness Type

What is a Memory Corruption Vulnerability?

The software writes data past the end, or before the beginning, of the intended buffer. Typically, this can result in corruption of data, a crash, or code execution. The software may modify an index or perform pointer arithmetic that references a memory location that is outside of the boundaries of the buffer. A subsequent write operation then produces undefined or unexpected results.

CVE-2026-84523 has been classified to as a Memory Corruption vulnerability or weakness.