CVE-2026-43766: Apple macOS Information Disclosure Flaw

CVE-2026-43766 Overview

CVE-2026-43766 is an authorization vulnerability in Apple macOS that allows an attacker with physical access to a locked device to view sensitive user information. Apple addressed the issue with improved state management. The flaw is classified under [CWE-287] Improper Authentication and requires local physical access to exploit.

Apple patched the vulnerability in macOS Sequoia 15.7.8, macOS Sonoma 14.8.8, and macOS Tahoe 26.6. No user interaction and no privileges are required, but the attack vector is physical, limiting large-scale exploitation.

Critical Impact
An attacker with physical possession of a locked Mac can bypass authorization controls to access confidential user data without unlocking the device.

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

Discovery Timeline

2026-07-27 - CVE-2026-43766 published to NVD
2026-07-28 - Last updated in NVD database

Technical Details for CVE-2026-43766

Vulnerability Analysis

The vulnerability stems from improper state management within an authorization workflow on macOS. When the device is in a locked state, certain code paths fail to correctly evaluate whether the user is authenticated before releasing protected information. An attacker with hands-on access to the target Mac can trigger these paths and observe sensitive data intended to remain protected behind the lock screen.

The underlying weakness maps to [CWE-287] Improper Authentication. Rather than enforcing a strict authenticated-versus-locked state check, the affected component relied on transient or incorrect state values. Apple's fix reinforces this state machine so that protected views and data cannot be reached without valid authentication.

Because the attack vector is physical, remote exploitation is not possible. The vulnerability is most relevant to lost, stolen, or unattended devices, along with scenarios such as border inspections, evil-maid attacks, and shared workspaces.

Root Cause

The root cause is inadequate state tracking within an authorization routine. The affected component permitted access to sensitive user information without confirming the device had transitioned out of the locked state.

Attack Vector

An attacker needs direct physical access to a locked Mac running an unpatched macOS version. By interacting with the device through supported input surfaces, the attacker triggers the vulnerable code path and views sensitive user information without providing credentials. See the Apple Support Article 128067, Apple Support Article 128071, and Apple Support Article 128072 for vendor guidance.

Detection Methods for CVE-2026-43766

Indicators of Compromise

Reports from users of unexplained data exposure following device loss, theft, or unattended access
macOS systems running versions older than 15.7.8, 14.8.8, or 26.6 in managed fleets
Devices returning from repair, transit, or third-party custody with signs of tampering or unauthorized handling

Detection Strategies

Inventory macOS endpoints and flag hosts whose OS build predates the fixed versions using MDM or endpoint telemetry
Correlate lock-screen bypass reports with physical custody events such as travel, loss reports, or shipping
Review authentication and unlock audit logs for anomalies around periods when the device was unattended

Monitoring Recommendations

Enforce continuous compliance checks that alert when macOS versions fall below the patched baselines
Monitor Find My, MDM check-in gaps, and location changes that indicate physical loss of custody
Track device wipe, remote lock, and account revocation events for devices reported missing

How to Mitigate CVE-2026-43766

Immediate Actions Required

Update all macOS endpoints to macOS Sequoia 15.7.8, macOS Sonoma 14.8.8, or macOS Tahoe 26.6
Prioritize patching for laptops and mobile Macs that leave controlled facilities
Remotely lock or wipe any Mac reported lost or stolen that has not yet been updated

Patch Information

Apple resolved CVE-2026-43766 through improved state management in the affected authorization component. Fixed versions are macOS Sequoia 15.7.8, macOS Sonoma 14.8.8, and macOS Tahoe 26.6. Refer to Apple Support Article 128067, Apple Support Article 128071, and Apple Support Article 128072 for release notes.

Workarounds

Enable FileVault full-disk encryption to reduce data exposure on locked or powered-off devices
Require a firmware password or Apple silicon recovery restrictions to limit boot-time tampering
Enforce short auto-lock intervals and disable lock-screen features that surface previews of sensitive content
Maintain physical custody controls and use tamper-evident storage for devices left unattended

bash

# Verify macOS build and enforce patched baseline
sw_vers -productVersion

# Trigger a software update check via MDM or locally
sudo softwareupdate --install --all --restart

# Confirm FileVault is enabled to mitigate physical-access exposure
fdesetup status