External risk intelligence

macOS Kernel Buffer Overflow Corrupts Memory

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2026-64767

The vulnerability affects core operating system components (macOS kernel) rather than an internet-facing service or application. Standard deployment of these OS versions involves local operation on end-user devices, and kernel-level vulnerabilities are typically not directly reachable or exploitable via public internet-facing interfaces in common deployment patterns.

Buffer Overflow

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

This advisory addresses a critical vulnerability in macOS that could allow a remote attacker to cause system termination or corrupt kernel memory. The issue has been resolved in recent macOS updates, and the main concern is confirming relevance and exposure within your environment.

Potential for system disruption.
Protects core operating system stability.
Verify relevance and scope.

Attack Path

How an attacker could exploit the issue

An attacker could exploit this vulnerability by sending specially crafted data over the network. This data would target a vulnerable component within the operating system, leading to a buffer overflow. When successful, this could result in the system unexpectedly shutting down or critical memory becoming corrupted.

No special access required.
Triggered by network data.
Risk of system termination or memory corruption.

Live Threat

Current exploitation, exposure, and threat context

A remote attacker could potentially cause unexpected system termination or corrupt kernel memory by exploiting a buffer overflow vulnerability. This could affect the overall stability and integrity of the affected macOS systems.

Kernel memory corruption and system termination.
Remote network access could trigger overflow.
System instability and data integrity risks.

Operational Fix

Recommended remediation, mitigation, and detection steps

This critical vulnerability impacts macOS kernel memory, making it a concern for infrastructure and platform teams responsible for OS integrity. The first practical step is to identify all macOS endpoints, confirm their reachability and business criticality, and then coordinate with asset owners to plan remediation.

Infrastructure and Platform Teams own.
Verify affected macOS endpoints.
Plan OS updates and patching.

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 macOS Sequoia, Sonoma, and Tahoe?

These are versions of the Apple macOS operating system. The kernel acts as the core foundation of these systems, managing communication between hardware and software. Vulnerabilities here affect the most fundamental layer of the computer, which handles memory, processes, and system stability across all user applications.

What does CWE-120 mean for CVE-2026-64767?

CWE-120 refers to a classic Buffer Overflow weakness. In this CVE, it means the system component failed to properly check the size of incoming data before writing it to a memory buffer. If the data exceeds the allocated space, it spills over into adjacent memory, which can lead to system crashes or allow memory corruption.

How can an attacker trigger this buffer overflow?

The vulnerability is triggered by sending specially crafted data over a network to the target system. It is important to note that normal, routine network traffic or standard user web browsing does not trigger this issue. The attack requires the delivery of specific, malicious data sequences designed to exploit the lack of bounds checking in the kernel.

Is my machine at risk via the internet?

According to Halo Surface Signal, this is very unlikely. While the vulnerability is network-based, it targets core kernel components that are not typically exposed as public-facing services. Because standard macOS deployments are designed for local end-user operation, direct, unauthenticated reachability from the public internet is not a common characteristic of these systems.

What should I do to address this CVE?

The primary response is to ensure your systems are updated to the versions where this issue was addressed: macOS Sequoia 15.7.8, Sonoma 14.8.8, or Tahoe 26.6. Start by identifying which endpoints in your environment are running older versions. Coordinate with your platform or IT teams to schedule and deploy these security updates to maintain system integrity and stability.

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.