CVE-2026-43659: Apple iPadOS Race Condition Vulnerability

CVE-2026-43659 Overview

CVE-2026-43659 is a race condition vulnerability affecting multiple Apple operating systems. A local application can exploit a timing flaw to access sensitive user data that should be protected by the operating system. Apple addressed the issue by adding validation checks in updated builds.

The flaw is tracked under CWE-362, concurrent execution using shared resources with improper synchronization. Exploitation requires local access and elevated attack complexity, limiting opportunistic abuse but not removing the risk for targeted scenarios.

Critical Impact
A malicious app installed on an affected Apple device can win a race condition to read sensitive user data that the operating system normally isolates between processes.

Affected Products

Apple iOS and iPadOS prior to 18.7.9 and prior to 26.5
Apple macOS Sonoma prior to 14.8.7, macOS Sequoia prior to 15.7.7, and macOS Tahoe prior to 26.5
Apple visionOS prior to 26.5

Discovery Timeline

2026-05-11 - CVE-2026-43659 published to the National Vulnerability Database
2026-05-12 - Last updated in NVD database

Technical Details for CVE-2026-43659

Vulnerability Analysis

The vulnerability is a race condition in Apple operating system components shared across iOS, iPadOS, macOS, and visionOS. Apple's advisory describes the fix as the addition of validation logic, indicating the original code path did not adequately verify state between a check and a subsequent use. An application running locally on the device can exploit this timing window to access sensitive user data.

The weakness maps to CWE-362. Race conditions of this class commonly enable Time-of-Check to Time-of-Use (TOCTOU) exploitation, where an attacker substitutes or modifies a resource between the moment a privileged component validates it and the moment that component uses it. Successful exploitation undermines confidentiality without affecting integrity or availability of the host system.

Root Cause

According to Apple, the original implementation contained a code path where access decisions were made without sufficient validation when concurrent operations executed against shared state. The remediation introduces additional validation to ensure the resource or condition observed during the check remains consistent at the time of use. Apple has not published the affected component name or function-level details in the public advisories.

Attack Vector

Exploitation requires an attacker to deliver a malicious application to the target device and execute code locally with low privileges. The attacker then triggers concurrent operations to win the race window and read sensitive user data accessible to the OS. No user interaction is required once the application is running. The high attack complexity reflects the timing precision needed to reliably exploit the race.

No public proof-of-concept code, exploit modules, or in-the-wild exploitation reports are associated with CVE-2026-43659. The vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog.

Detection Methods for CVE-2026-43659

Indicators of Compromise

No vendor-published indicators of compromise are available for CVE-2026-43659.
Unexpected installation of unsigned or sideloaded applications on managed Apple devices should be treated as suspicious in the context of local privilege and data-access flaws.

Detection Strategies

Inventory Apple endpoints and compare installed OS build numbers against the patched versions listed in Apple Support Documents 127110, 127111, 127115, 127116, 127117, and 127120.
Monitor MDM compliance reports for devices running iOS/iPadOS below 18.7.9 or 26.5, macOS below 14.8.7, 15.7.7, or 26.5, and visionOS below 26.5.
Review application telemetry for processes invoking sensitive entitlement-gated APIs at high frequency or with abnormal concurrency patterns.

Monitoring Recommendations

Forward macOS Endpoint Security and Unified Log events related to entitlement checks and sandbox enforcement to a centralized analytics platform.
Track app installation events from non-App Store sources on macOS and from enterprise or developer distribution channels on iOS, iPadOS, and visionOS.
Alert on devices that remain unpatched beyond a defined remediation window after Apple's advisories.

How to Mitigate CVE-2026-43659

Immediate Actions Required

Update iOS and iPadOS to 18.7.9 or 26.5, macOS to Sonoma 14.8.7, Sequoia 15.7.7, or Tahoe 26.5, and visionOS to 26.5.
Enforce minimum OS versions through MDM policies and block enrollment or network access for devices below the patched baselines.
Restrict installation of untrusted applications, including sideloaded and developer-signed builds, on managed devices.

Patch Information

Apple has released fixes in iOS 18.7.9, iPadOS 18.7.9, iOS 26.5, iPadOS 26.5, macOS Sonoma 14.8.7, macOS Sequoia 15.7.7, macOS Tahoe 26.5, and visionOS 26.5. Refer to Apple Support Document 127110, Apple Support Document 127111, Apple Support Document 127115, Apple Support Document 127116, Apple Support Document 127117, and Apple Support Document 127120 for the advisory matching each platform.

Workarounds

No vendor-supplied workaround exists; patching is the only supported remediation.
Limit exposure by allowing only vetted applications from the App Store and trusted enterprise sources until updates are deployed.
Apply principle of least privilege to user accounts on shared macOS systems to reduce the data exposed to a local attacker.

bash

# Verify the running OS build on macOS and compare against patched versions
sw_vers

# Verify the running OS build on iOS, iPadOS, or visionOS via MDM query
# Example: query the ProductVersion key returned in a DeviceInformation command