External risk intelligence

macOS Out-of-Bounds Read Allows Unexpected System Termination.

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2026-64762

The vulnerability affects local operating system components on macOS. It is a client-side issue where a local application could trigger system termination, rather than a service, gateway, or network-exposed application that would be reachable from the public internet.

Out-of-bounds Read

Apple Macos

14.0 to before 14.8.815.0 to before 15.7.826.0 to before 26.6

Halo Surface Signal: 1 out of 5 — much less likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

A critical vulnerability has been identified in macOS that could potentially lead to unexpected system termination if an application is able to trigger the issue through an out-of-bounds read. While this could impact system stability, the primary concern is confirming if our specific macOS environments are affected and to what extent.

System instability from an app error.
Potential for unexpected system termination.
Confirm relevance and exposure in our environment.

Attack Path

How an attacker could exploit the issue

An attacker could exploit this vulnerability by tricking a user into running a specially crafted application on their macOS system. This application could then attempt to read data beyond the expected boundaries of a memory buffer. If successful, this action could lead to the application, and potentially the entire system, unexpectedly terminating.

No privileges or user interaction needed.
Crafted app triggers memory bounds error.
Risk of unexpected system termination.

Live Threat

Current exploitation, exposure, and threat context

A potential out-of-bounds read vulnerability could allow a malicious application to trigger an unexpected system termination on macOS. This occurs when an app attempts to read data beyond its allocated memory boundaries, leading to instability.

System termination could occur.
App may read out of bounds.
Unexpected shutdown of the OS.

Operational Fix

Recommended remediation, mitigation, and detection steps

This vulnerability affects macOS systems. Infrastructure or endpoint teams are likely responsible for identifying and managing affected systems. The first practical step is to inventory all macOS devices, determine their exposure, and confirm which are business-critical to prioritize remediation efforts.

Ownership: Endpoint and infrastructure teams.
Verify first: Identify all macOS systems.
Action: Plan and execute OS updates.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

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Frequently asked questions

What is the software affected by CVE-2026-64762?

This CVE impacts the macOS operating system, specifically versions of Sequoia, Sonoma, and Tahoe. macOS serves as the core platform that manages hardware resources and runs all user applications. This vulnerability relates to how the system handles memory, which is a fundamental task for the underlying OS kernel and associated services to maintain stability for every program you run.

How would you explain the CVE-2026-64762 vulnerability?

This issue is classified as an out-of-bounds read (CWE-125). In simple terms, think of it like a computer program looking at a shelf for information but reaching past the shelf's edge into unauthorized space. Because the system does not properly check the boundaries of where it is allowed to read, attempting to access this out-of-bounds memory causes the software to trip over itself, resulting in an unexpected system shutdown.

Does running a normal app trigger this vulnerability?

No. A standard, legitimate application will not trigger this issue. The vulnerability requires a specifically crafted application designed to deliberately attempt to read memory outside of its permitted range. If an application is behaving normally and following standard memory access protocols, it does not encounter this specific memory bounds error.

Is my machine reachable from the internet?

Halo Surface Signal indicates that this is a client-side issue, meaning it affects local macOS components. It is very unlikely to be triggered by remote network traffic because it requires an application to be running locally on the system. It is not a service or gateway exposed to the public internet that could be attacked remotely without local code execution.

What is the first step to address CVE-2026-64762?

The most effective way to secure your systems is to update your macOS to the versions noted in the security release, such as Sequoia 15.7.8, Sonoma 14.8.8, or Tahoe 26.6. Begin by creating an inventory of your macOS devices to identify which ones are running older versions. Once identified, prioritize these devices for the standard operating system update process to apply the necessary bounds-checking improvements.

References

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.