CVE-2026-43759: Apple macOS Information Disclosure Flaw

CVE-2026-43759 Overview

CVE-2026-43759 is an authorization vulnerability affecting Apple macOS and watchOS. The flaw stems from improper state management in an authorization check, allowing a locally installed application to access sensitive user data without proper authorization. Apple addressed the issue with improved state management in macOS Tahoe 26.6 and watchOS 26.6. The vulnerability is categorized under [CWE-200] (Exposure of Sensitive Information to an Unauthorized Actor) and requires local access with user interaction to exploit.

Critical Impact
A malicious application installed on a vulnerable macOS or watchOS device can bypass authorization controls to read sensitive user data, exposing confidential information such as personal files, credentials, or other user-scoped content.

Affected Products

Apple macOS (versions prior to macOS Tahoe 26.6)
Apple watchOS (versions prior to watchOS 26.6)
Applications relying on the affected authorization component for data protection

Discovery Timeline

2026-07-27 - CVE-2026-43759 published to the National Vulnerability Database (NVD)
2026-07-28 - Last updated in NVD database

Technical Details for CVE-2026-43759

Vulnerability Analysis

CVE-2026-43759 is an authorization flaw rooted in improper state management within an Apple operating system component shared across macOS and watchOS. When the affected component evaluates whether a caller is permitted to access protected data, transient or inconsistent state allows the authorization check to be satisfied under conditions where it should not be. The result is that an application without the required entitlements or user consent can reach sensitive user data. Apple's advisory language, "An app may be able to access sensitive user data," reflects a confidentiality impact without direct integrity or availability consequences. The vulnerability requires local execution context and user interaction, which typically means the victim runs or installs the malicious app.

Root Cause

The root cause is improper state management in an authorization routine. Rather than a missing check, the code performs an authorization decision using state that can be stale, inconsistent, or manipulable across sequential operations. Apple's fix explicitly re-architects the state management flow so the authorization decision reflects the actual, current permission state of the caller.

Attack Vector

Exploitation requires an attacker to deliver and execute a crafted application on the target device. Once running, the application invokes the vulnerable authorization path and reads protected user data that would otherwise be gated by consent or entitlement checks. No network access is required, and the attacker gains no code execution or persistence primitive beyond what the malicious app already possesses; the impact is data disclosure.

No public proof-of-concept exploit is available for CVE-2026-43759, and the vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog. Technical specifics beyond Apple's brief advisory language have not been published. Refer to the Apple Support Article 128067 and Apple Support Article 128068 for vendor guidance.

Detection Methods for CVE-2026-43759

Indicators of Compromise

Installation or execution of unsigned or untrusted third-party applications on macOS or watchOS-paired devices running versions prior to 26.6.
Unexpected access to user-scoped data stores (Contacts, Photos, Calendars, or app sandbox data) by applications that were never granted the corresponding TCC consent.
Apps requesting elevated capabilities inconsistent with their stated function or advertised entitlements.

Detection Strategies

Inventory endpoints and identify macOS hosts running versions below macOS Tahoe 26.6 and paired watchOS devices below watchOS 26.6.
Monitor Unified Log entries related to TCC (com.apple.TCC) for anomalous authorization decisions or repeated access attempts from the same process.
Correlate application install events with subsequent access to sensitive user directories such as ~/Library/Application Support, ~/Library/Messages, and ~/Library/Containers.

Monitoring Recommendations

Enable endpoint telemetry that captures process execution, code signing status, and file access on macOS fleets.
Alert on newly installed applications that read from privacy-protected locations shortly after first launch.
Track macOS and watchOS version compliance in your asset management platform and flag devices that have not upgraded to the patched release.

How to Mitigate CVE-2026-43759

Immediate Actions Required

Update all macOS endpoints to macOS Tahoe 26.6 and all paired Apple Watches to watchOS 26.6 through Software Update or your MDM platform.
Audit installed applications on affected devices and remove any untrusted, unsigned, or unnecessary third-party apps.
Enforce Gatekeeper and Notarization policies to prevent execution of applications from unidentified developers.

Patch Information

Apple released fixes in macOS Tahoe 26.6 and watchOS 26.6. Deployment details are documented in Apple Support Article 128067 and Apple Support Article 128068. Managed fleets should push the update through MDM using configuration profiles that enforce minimum OS versions.

Workarounds

No vendor-supplied workaround exists; applying the OS update is the only supported remediation.
Restrict application installation to the Mac App Store or notarized developers via MDM configuration until patches are deployed.
Review and tighten TCC (Transparency, Consent, and Control) permissions granted to third-party applications, revoking access that is not strictly required.

bash

# Verify installed macOS version meets the patched baseline
sw_vers -productVersion

# MDM-style enforcement: require macOS 26.6 or later before enrollment
# (example configuration profile key)
# <key>MinimumOSVersion</key>
# <string>26.6</string>