CVE-2026-43743: Apple iPadOS Race Condition Vulnerability

CVE-2026-43743 Overview

CVE-2026-43743 is a race condition vulnerability affecting Apple iOS, iPadOS, and macOS Tahoe operating systems. The flaw stems from improper state handling and can be triggered by a malicious application to cause unexpected system termination. Apple addressed the issue with improved state handling in iOS 26.5.2, iPadOS 26.5.2, and macOS Tahoe 26.5.2. The vulnerability is classified under [CWE-362] (Concurrent Execution using Shared Resource with Improper Synchronization) and requires local access with low privileges. No public exploit code is available, and the flaw is not listed in the CISA Known Exploited Vulnerabilities catalog.

Critical Impact
A local application can trigger a race condition that leads to unexpected system termination, resulting in denial of service on affected Apple devices.

Affected Products

Apple iOS (versions prior to 26.5.2)
Apple iPadOS (versions prior to 26.5.2)
Apple macOS Tahoe (versions prior to 26.5.2)

Discovery Timeline

2026-06-29 - CVE-2026-43743 published to the National Vulnerability Database
2026-06-30 - Last updated in NVD database

Technical Details for CVE-2026-43743

Vulnerability Analysis

CVE-2026-43743 is a race condition [CWE-362] in Apple's operating systems. Race conditions occur when multiple execution threads access shared state without proper synchronization. In this case, the flaw allows a local application to exploit the timing window during state transitions to force the system into an inconsistent state. The result is unexpected system termination, which disrupts device availability. Apple resolved the issue by introducing improved state handling logic in the affected components.

Root Cause

The root cause lies in insufficient synchronization when handling concurrent state changes within a shared kernel or system resource. When two operations interact with the same state without atomic guarantees, an attacker with local code execution can align operations to interleave in a way that violates state invariants. This produces a fault condition that the operating system cannot recover from without termination.

Attack Vector

An attacker must first achieve local code execution on the target device, typically through a malicious application. The exploitation requires high attack complexity because timing conditions must align precisely to trigger the race. Successful exploitation does not allow the attacker to read, modify, or execute arbitrary code — it only impacts availability. Apple's advisories for iOS/iPadOS 26.5.2 and macOS Tahoe 26.5.2 describe the fix as improved state handling.

No verified proof-of-concept code is publicly available. Detailed exploitation mechanics have not been disclosed by Apple or third-party researchers at the time of publication.

Detection Methods for CVE-2026-43743

Indicators of Compromise

Unexpected kernel panics or system reboots on iOS, iPadOS, or macOS devices running versions prior to 26.5.2
Crash reports in /Library/Logs/DiagnosticReports/ (macOS) referencing abrupt state transitions or synchronization faults
Recently installed or sideloaded applications preceding repeated system terminations

Detection Strategies

Review MDM telemetry for devices running vulnerable OS versions and correlate with crash frequency metrics
Inspect application inventories for untrusted or unsigned binaries with unusual system-level activity
Monitor endpoint logs for repeated abnormal shutdown events that coincide with third-party application execution

Monitoring Recommendations

Enable centralized crash log collection across managed Apple endpoints
Track OS version compliance and flag devices not updated to iOS/iPadOS/macOS 26.5.2 or later
Alert on repeated system termination events tied to specific application bundle identifiers

How to Mitigate CVE-2026-43743

Immediate Actions Required

Update all Apple devices to iOS 26.5.2, iPadOS 26.5.2, or macOS Tahoe 26.5.2 without delay
Audit installed applications and remove untrusted or unnecessary third-party software
Enforce update compliance through mobile device management (MDM) policies

Patch Information

Apple released fixes in iOS 26.5.2, iPadOS 26.5.2, and macOS Tahoe 26.5.2. Full patch details are available in Apple Support Article 127594 and Apple Support Article 127595. The fix introduces improved state handling to eliminate the race condition.

Workarounds

Restrict installation of applications to trusted sources such as the App Store
Enable automatic OS updates on all managed Apple devices
Limit local user privileges on macOS systems to reduce the pool of accounts able to run arbitrary applications

bash

# Verify installed OS version on macOS
sw_vers -productVersion

# Verify installed OS version on iOS/iPadOS via MDM query or Settings > General > About
# Expected output: 26.5.2 or later