CVE-2026-65398 Overview
CVE-2026-65398 is an out-of-bounds access vulnerability affecting multiple Apple operating systems. A malicious application running locally can trigger unexpected system termination or corrupt kernel memory. Apple addressed the flaw with improved bounds checking across its OS families.
The issue impacts iOS 27, iPadOS 27, macOS Golden Gate 27, tvOS 27, visionOS 27, and watchOS 27. The vulnerability is classified under [CWE-120] Buffer Copy without Checking Size of Input. Exploitation requires local access with low privileges and no user interaction.
Critical Impact
A locally installed app can corrupt kernel memory or terminate the system, providing a foothold for privilege escalation on Apple devices across the entire product line.
Affected Products
- Apple iOS 27 and iPadOS 27
- Apple macOS Golden Gate 27
- Apple tvOS 27, visionOS 27, and watchOS 27
Discovery Timeline
- 2026-09-14 - CVE-2026-65398 published to NVD
- 2026-09-17 - Last updated in NVD database
Technical Details for CVE-2026-65398
Vulnerability Analysis
The vulnerability is an out-of-bounds access condition in Apple operating system components. When an application supplies crafted input, the affected code reads or writes memory beyond an allocated buffer boundary. This can crash the system or overwrite kernel data structures.
The defect maps to [CWE-120], indicating that a buffer operation proceeds without validating that the source data fits within destination bounds. Because the affected code path executes within kernel context, corrupted memory can compromise system integrity. Apple's fix introduces additional bounds checking before the memory operation is performed.
Root Cause
The root cause is missing or insufficient bounds validation in a kernel-accessible code path shared across Apple's operating system platforms. Local applications reach this code path through standard system interfaces available to unprivileged processes.
Attack Vector
Exploitation requires local code execution on the target device. An attacker delivers a malicious app, or compromises a legitimate one, and invokes the vulnerable interface with crafted parameters. Successful exploitation yields kernel memory corruption or a denial-of-service condition affecting the entire device.
No authentication beyond standard app sandbox privileges is required, and no user interaction is needed once the malicious app runs. See the Apple Support advisories for platform-specific technical details.
Detection Methods for CVE-2026-65398
Indicators of Compromise
- Unexpected kernel panics or system reboots on Apple devices running the affected OS versions
- Repeated application crashes referencing the same system framework or driver
- Presence of unsigned or newly installed apps immediately preceding stability issues
Detection Strategies
- Collect and analyze crash reports from managed Apple devices for kernel-level faults matching out-of-bounds access signatures
- Correlate MDM inventory data against fixed OS versions to surface devices still exposed to CVE-2026-65398
- Monitor endpoint telemetry for anomalous process behavior originating from sandboxed applications interacting with low-level system APIs
Monitoring Recommendations
- Enable centralized crash log aggregation from macOS endpoints and mobile device management platforms
- Alert on repeated panic events referencing kernel extensions or shared subsystems on affected OS builds
- Track new application installations on managed fleets and flag apps that trigger stability regressions post-install
How to Mitigate CVE-2026-65398
Immediate Actions Required
- Update all Apple devices to iOS 27, iPadOS 27, macOS Golden Gate 27, tvOS 27, visionOS 27, or watchOS 27 as applicable
- Inventory devices through MDM to identify systems running vulnerable prior releases
- Restrict installation of untrusted applications on managed endpoints until patching completes
Patch Information
Apple has released fixes across all affected platforms. Refer to the official Apple advisories for build numbers and rollout guidance: Apple Support Document #149034, #149035, #149036, #149037, and #149038.
Workarounds
- No official workarounds are published by Apple; upgrading to the fixed OS versions is the required remediation
- Enforce App Store-only installation policies via MDM to reduce exposure to malicious local applications
- Apply the principle of least privilege for user accounts and disable developer mode on production devices
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
