External risk intelligence

Apple Out-of-Bounds Write Vulnerability Affects Multiple Operating Systems

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2026-64770

This vulnerability affects end-user operating systems (iOS, iPadOS, macOS, tvOS, visionOS) and their built-in components. These platforms are typically personal, client-side devices not deployed as internet-facing servers or public gateways, and their common use case does not involve hosting publicly reachable services that would expose this attack surface to the internet.

Out-of-bounds Write

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

This vulnerability involves an out-of-bounds write in Apple's operating systems, potentially leading to application crashes or memory corruption if exploited remotely. While it affects user-facing devices, the primary concern at this stage is to confirm if any specific business-critical applications or custom configurations are exposed.

Unexpected application crashes or memory corruption.
Understand its relevance to our specific device usage.
Assess exposure and confirm unaffected systems.

Attack Path

How an attacker could exploit the issue

An attacker could exploit this vulnerability by sending specially crafted data over the network to a vulnerable system. This could lead to an application unexpectedly terminating or experiencing heap corruption, potentially allowing for further compromise.

No privileges or user interaction required.
Remote network data transmission.
Application crash or memory corruption.

Live Threat

Current exploitation, exposure, and threat context

This vulnerability could allow a remote attacker to trigger unexpected application termination or heap corruption. The provided context does not indicate any specific user data or PII at risk.

Application stability and integrity.
Exploited via network connection.
Potential for denial of service.

Operational Fix

Recommended remediation, mitigation, and detection steps

Ownership of this vulnerability likely resides with teams managing end-user devices and operating systems, such as IT or endpoint management. The immediate priority is to determine the scope of affected devices and their business criticality. Following this, coordinating with vendor security advisories for official remediation guidance and planning for patch deployment during scheduled maintenance windows will be crucial.

End-user device and OS owners.
Verify affected device presence and criticality.
Plan and deploy OS and application 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-2026-64770?

This vulnerability affects Apple's core operating systems, including iOS, iPadOS, macOS (Sequoia, Sonoma, and Tahoe), tvOS, and visionOS. These platforms power a wide range of devices—such as iPhones, iPads, Mac computers, Apple TV, and Apple Vision Pro—that users rely on daily for communication, productivity, and media consumption.

What does out-of-bounds write mean for CVE-2026-64770?

Classified as CWE-787, an out-of-bounds write occurs when software writes data past the intended memory buffer limits. In this CVE, it means the system accidentally allows data to be placed in an unauthorized memory location. This can overwrite adjacent data, leading to application crashes or potentially corrupting the heap, which is memory used for dynamic tasks.

How can an attacker trigger this vulnerability?

An attacker can trigger this by sending specially crafted data over a network to a vulnerable device. Crucially, this does not require the attacker to have existing privileges, nor does it require any action from the user. Simply receiving or processing this malicious network data is enough to potentially crash an application or corrupt memory.

Is my device at risk based on Halo Surface Signal?

Halo Surface Signal indicates it is very unlikely for these devices to face direct internet-facing server threats. Because these are client-side operating systems, they are generally not used as public gateways. While still important to secure, they typically lack the hosting functions that would make them easy targets for this specific type of remote network attack.

What steps should I take to address CVE-2026-64770?

The primary response is to identify all managed devices running the affected operating systems and plan for updates. Coordinate with your IT or endpoint management teams to confirm which versions you are using. Since this is an OS-level issue, official remediation involves applying the patches provided by Apple in the latest software updates to ensure system stability and integrity.

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.