External risk intelligence

Integer Overflow in Apple Operating Systems Allows Unexpected System Termination

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2026-43769

This vulnerability affects client-side operating systems and platforms (iOS, iPadOS, macOS, tvOS, visionOS, watchOS). These products are typically used as end-user devices rather than internet-facing servers or edge services, and exploitation generally requires the execution of a malicious application on the local device.

Integer Overflow

Apple Ipados

before 26.614.0 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

An integer overflow vulnerability has been identified in Apple's operating systems. While the specific impact is described as an application potentially causing unexpected system termination, the severity suggests a broader potential for disruption if exploited. The primary concern at this stage is confirming if these operating systems are in use within our environment.

Flaw allows apps to crash systems unexpectedly.
Critical severity; confirm if our systems use affected technology.
Understand exposure and potential for disruption.

Attack Path

How an attacker could exploit the issue

An attacker could leverage an integer overflow vulnerability by sending specially crafted input to an application, potentially leading to unexpected system termination. This means an app could be used to crash the system.

No special access needed.
Vulnerable application input.
Unexpected system termination.

Live Threat

Current exploitation, exposure, and threat context

An integer overflow vulnerability could allow an app to cause unexpected system termination under certain conditions.

System stability may be affected.
Unexpected app behavior or termination.
Disruption of device services.

Operational Fix

Recommended remediation, mitigation, and detection steps

This vulnerability impacts Apple's client operating systems, making device owners and potentially infrastructure teams responsible for remediation. The first practical step is to identify all affected devices within the environment, determine their reachability and criticality, and then initiate a plan for updating the operating systems.

Device owners and IT infrastructure teams own the issue.
Verify affected Apple devices and their reachability.
Plan OS updates during maintenance windows.

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-2026-43769?

This vulnerability impacts Apple's ecosystem, specifically iOS, iPadOS, macOS (Sequoia, Sonoma, Tahoe), tvOS, visionOS, and watchOS. These platforms serve as the core operating systems for Apple's wide range of personal computing, mobile, and wearable devices, managing system resources and running both native and third-party applications.

How does an integer overflow lead to system termination?

An integer overflow (CWE-190) occurs when a calculation produces a value too large for the system's memory allocation to handle. In this CVE, the flaw exists in how the operating system processes input. When provided with specific, malformed data, the system encounters this calculation error, causing it to fail and terminate unexpectedly to prevent further instability.

Do I need to be logged into a system to trigger this bug?

No, this does not require special administrative access or authentication. The vulnerability is triggered by providing specially crafted input to a vulnerable application. Note that simply viewing legitimate content or running standard, non-malicious apps does not trigger this issue; it requires an interaction designed to exploit the specific integer overflow condition.

Is my device at risk according to Halo Surface Signal?

Halo Surface Signal indicates that while the vulnerability is severe, it affects client-side operating systems rather than internet-facing servers. Because exploitation generally requires a malicious application to be running locally on the device, the risk is typically contained to individual endpoints rather than the broader network infrastructure.

When should I prioritize updating my devices?

You should initiate your update plan as soon as possible. The primary defense against this vulnerability is applying the OS updates (version 26.6 or specified macOS versions) provided by Apple. Start by auditing your inventory to locate all affected devices, then schedule these updates during your standard maintenance windows to restore system stability and address the flaw.

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.