CVE-2026-43770: Apple macOS Race Condition Vulnerability

CVE-2026-43770 Overview

CVE-2026-43770 is a race condition vulnerability [CWE-362] affecting Apple macOS and tvOS. The flaw allows a local application to access sensitive user data by exploiting a timing window during resource access. Apple addressed the issue with additional validation in the affected code path.

The vulnerability is fixed in macOS Sequoia 15.7.8, macOS Sonoma 14.8.8, macOS Tahoe 26.6, and tvOS 26.6. Exploitation requires local access and user interaction, and attack complexity is high, which limits practical exploitation in most environments.

Critical Impact
A malicious application running locally can win a race condition to read sensitive user data that should be protected by system access controls.

Affected Products

Apple macOS Sequoia (versions prior to 15.7.8)
Apple macOS Sonoma (versions prior to 14.8.8)
Apple macOS Tahoe (versions prior to 26.6)
Apple tvOS (versions prior to 26.6)

Discovery Timeline

2026-07-27 - CVE-2026-43770 published to the National Vulnerability Database
2026-07-29 - Last updated in NVD database

Technical Details for CVE-2026-43770

Vulnerability Analysis

CVE-2026-43770 is classified as a race condition [CWE-362], also known as a concurrent execution flaw. The affected macOS and tvOS component performs a security-relevant check and a subsequent action on shared state without maintaining atomicity between the two operations. An attacker that can execute code locally may interleave operations to bypass the validation and access data that should be restricted.

Apple's advisory states the issue was addressed with additional validation, indicating the fix reinforces state checks so that intervening changes cannot invalidate the earlier check. The vulnerability affects both desktop (macOS) and TV (tvOS) code paths, suggesting the flawed logic resides in a shared framework or system service.

Successful exploitation impacts confidentiality only. The advisory reports no integrity or availability impact, consistent with sensitive data disclosure rather than code execution or system disruption.

Root Cause

The root cause is a time-of-check to time-of-use (TOCTOU) style race. The vulnerable code validates access to a resource, but the state can change between validation and the operation that consumes the resource. An attacker who wins the race obtains sensitive user data that the validation would otherwise block.

Attack Vector

Exploitation requires local code execution on the target device, typically through an installed application. The attacker must also induce user interaction and reliably win a timing window, which raises the attack complexity. No elevated privileges are required prior to exploitation.

Because the flaw is reachable from an unprivileged app context, malicious software distributed through side-loading, unsigned installers, or social engineering represents a realistic delivery path.

// No public proof-of-concept exploit code is available for CVE-2026-43770.
// See the Apple security advisories linked in the References for vendor details.

Detection Methods for CVE-2026-43770

Indicators of Compromise

No public indicators of compromise have been published for CVE-2026-43770.
The vulnerability is not listed on the CISA Known Exploited Vulnerabilities catalog and no in-the-wild exploitation has been reported.

Detection Strategies

Inventory macOS and tvOS assets and compare installed build numbers against the fixed versions (15.7.8, 14.8.8, 26.6, tvOS 26.6).
Monitor for unsigned or newly installed applications that request access to protected user data locations such as ~/Library, Contacts, Calendars, or Photos.
Review endpoint telemetry for processes that perform rapid, repeated access attempts against the same file or IPC endpoint, which is characteristic of race-condition exploitation.

Monitoring Recommendations

Enable Endpoint Security framework logging on macOS to capture file access events and process spawn activity.
Alert on Transparency, Consent, and Control (TCC) prompt bypass patterns and unexpected access to protected user data domains.
Correlate application installation events with subsequent sensitive-data access to identify anomalous behavior post-install.

How to Mitigate CVE-2026-43770

Immediate Actions Required

Update all macOS endpoints to Sequoia 15.7.8, Sonoma 14.8.8, or Tahoe 26.6 as appropriate for the deployed release train.
Update Apple TV devices running tvOS to version 26.6.
Restrict installation of untrusted applications and enforce Gatekeeper and notarization requirements through management policy.

Patch Information

Apple released fixes across four security advisories covering the affected platforms. Refer to the vendor updates for build numbers and release notes:

Workarounds

No vendor-supplied workaround exists; applying the security update is the only supported remediation.
Reduce exposure by limiting local application installation to signed and notarized software from trusted sources.
Enforce least-privilege for user accounts and remove unused third-party applications that could serve as a delivery vehicle.

bash

# Verify installed macOS version and initiate software update check
sw_vers
sudo softwareupdate -l
sudo softwareupdate -i -a --restart