External risk intelligence

macOS Buffer Overflow Allows Code Execution

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2026-43750

This vulnerability affects macOS system components and requires an application to execute code to exploit the sandbox or privilege escalation. It is inherently client-side and local in nature, lacking the characteristics of an internet-facing service, gateway, or public endpoint.

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

A critical vulnerability has been identified in macOS that could allow an application to execute code beyond its intended permissions, potentially impacting system integrity. This issue has been addressed in recent macOS updates.

Flaw lets apps break out of restrictions.
Critical risk if unpatched; impacts system integrity.
Confirm relevance and exposure for macOS systems.

Attack Path

How an attacker could exploit the issue

An attacker could leverage this vulnerability by tricking a user into running a malicious application. This application could then exploit a buffer overflow in a macOS system component, potentially leading to arbitrary code execution.

Requires user to run a malicious app.
Exploits a buffer overflow in system component.
Allows code execution outside its sandbox.

Live Threat

Current exploitation, exposure, and threat context

A buffer overflow vulnerability, when exploited, could allow an application to execute arbitrary code, potentially bypassing sandbox restrictions or gaining elevated privileges on macOS systems. This could affect system data and service behavior under specific conditions.

System data and service integrity.
App could execute code outside sandbox.
Unauthorized code execution.

Operational Fix

Recommended remediation, mitigation, and detection steps

This vulnerability impacts macOS system components, suggesting that teams responsible for endpoint management and operating system patching are the primary stakeholders. The first practical step is to identify all macOS devices within the environment, determine their current macOS version, and prioritize remediation for any devices running versions prior to the security updates. Confirming the business criticality and user base of affected systems will inform the urgency and scheduling of the update process.

Endpoint management teams own this issue.
Verify macOS versions across devices.
Plan and schedule operating system 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 macOS software affected by CVE-2026-43750?

This vulnerability impacts core macOS system components across several major versions, including Sequoia 15.7.8, Sonoma 14.8.8, and Tahoe 26.6. These components act as the foundational software layer that manages permissions, hardware resources, and application sandboxing. When these systems are outdated, they may fail to properly restrict how individual apps interact with the underlying operating system.

What does buffer overflow mean in the context of this CVE?

This CVE involves a CWE-120 weakness, which happens when a program writes more data to a memory buffer than it can hold. Think of it like trying to pour a gallon of water into a pint-sized cup; the excess spills over into adjacent memory spaces. By precisely controlling this 'spill,' an attacker can overwrite system instructions, effectively tricking the computer into running unauthorized code instead of the intended application functions.

How is this CVE-2026-43750 vulnerability triggered?

An attacker needs a user to execute a malicious application to trigger this flaw. Simply browsing a website or receiving a file is not enough; the malicious code must actually run on the system to attempt the memory overwrite. If no untrusted or suspicious applications are executed, the specific conditions required to exploit this buffer overflow are not met.

Is my system at risk according to Halo Surface Signal?

Halo Surface Signal notes that this is a client-side issue, not an internet-facing service or public endpoint. Because it requires an application to be running locally to bypass sandbox restrictions, the risk is linked to the software installed on your macOS devices rather than exposed network services. This makes it primarily a local security concern rather than a remote network attack vector.

What is the first step to address this macOS vulnerability?

The most effective way to secure your environment is to identify all macOS devices in your fleet and verify their current version. Prioritize updating any systems running versions older than macOS Sequoia 15.7.8, Sonoma 14.8.8, or Tahoe 26.6. Since these updates include the necessary bounds checking improvements to prevent the buffer overflow, applying the official Apple patches is the standard and necessary path to remediation.

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.