CVE-2026-84576: Apple macOS Information Disclosure Flaw

CVE-2026-84576 Overview

CVE-2026-84576 is an information disclosure vulnerability affecting Apple macOS. A local application may be able to access sensitive user data due to insufficient validation checks. Apple addressed the issue with improved checks across three supported macOS releases. The weakness is classified under [CWE-200] (Exposure of Sensitive Information to an Unauthorized Actor). The vulnerability requires local access and low privileges, and does not require user interaction. No public proof-of-concept exploit is available, and the flaw is not listed in the CISA Known Exploited Vulnerabilities catalog.

Critical Impact
A locally installed application can read sensitive user data outside its intended sandbox or permission scope on affected macOS versions.

Affected Products

Apple macOS Tahoe versions prior to 26.7
Apple macOS Sequoia versions prior to 15.8
Apple macOS versions prior to Golden Gate 27

Discovery Timeline

2026-09-14 - CVE-2026-84576 published to NVD
2026-09-16 - Last updated in NVD database

Technical Details for CVE-2026-84576

Vulnerability Analysis

CVE-2026-84576 is an information disclosure flaw in macOS. Apple's advisory states that the issue was addressed with improved checks. The vulnerability allows an application running locally on the system to obtain data it should not be authorized to read.

The weakness maps to [CWE-200], which covers the exposure of sensitive information to actors that lack authorization. The attack surface is local, meaning an adversary must already have code execution on the host through a malicious or compromised application. No user interaction is required to trigger the flaw once the malicious app is running. The scope of exposed data depends on the affected macOS subsystem, but Apple's guidance classifies it as sensitive user data.

Root Cause

Apple's advisory attributes the issue to missing or insufficient validation checks in an unspecified macOS component. The fix introduces stricter checks to enforce access boundaries before returning data to a calling process. Apple has not disclosed the specific framework or service involved, consistent with the vendor's disclosure practices for local information disclosure issues.

Attack Vector

Exploitation requires local execution on the target Mac with low-privilege user rights. A threat actor delivers a crafted application through phishing, sideloading, a supply chain compromise, or a package repository. Once executed, the application queries the vulnerable macOS component and receives sensitive data that the operating system should have withheld. Because no user interaction is required after the app runs, the flaw is useful as a post-compromise data-collection primitive rather than as an initial-access vector.

No verified proof-of-concept code is available for this vulnerability. Refer to the Apple Support Article #149035, Apple Support Article #149042, and Apple Support Article #149043 for vendor guidance.

Detection Methods for CVE-2026-84576

Indicators of Compromise

Unsigned or ad-hoc signed applications executing from user-writable directories such as ~/Downloads, ~/Library, or /tmp.
Unexpected reads from privacy-protected locations or TCC-protected resources by non-system processes.
Newly installed applications making atypical XPC or IPC calls to system services immediately after launch.

Detection Strategies

Monitor endpoint telemetry for processes accessing sensitive user directories without a corresponding TCC prompt or entitlement.
Correlate application installation events with subsequent access to files under ~/Library/Application Support, ~/Library/Containers, and keychain paths.
Track process lineage to identify child processes spawned by recently installed or untrusted binaries.

Monitoring Recommendations

Enable macOS Endpoint Security framework telemetry and forward events to a centralized analytics platform.
Alert on execution of binaries lacking a valid Developer ID signature or notarization ticket.
Baseline normal file-access patterns per application and flag deviations that touch sensitive user data.

How to Mitigate CVE-2026-84576

Immediate Actions Required

Upgrade affected systems to macOS Golden Gate 27, macOS Sequoia 15.8, or macOS Tahoe 26.7 as appropriate for the hardware.
Inventory macOS endpoints and prioritize patching for systems that handle sensitive data or run untrusted third-party applications.
Restrict installation of unsigned or non-notarized applications through Gatekeeper policy and MDM configuration.

Patch Information

Apple has released fixes in macOS Golden Gate 27, macOS Sequoia 15.8, and macOS Tahoe 26.7. See Apple Support Article #149035, Apple Support Article #149042, and Apple Support Article #149043 for the corresponding release notes and download instructions.

Workarounds

Enforce Gatekeeper in its strictest mode to block execution of applications from unidentified developers.
Limit standard user accounts from installing third-party software and require administrator approval for new applications.
Review Transparency, Consent, and Control (TCC) permissions and revoke unnecessary access to Full Disk Access, Files and Folders, and other privacy-protected categories.

bash

# Verify installed macOS version against the patched releases
sw_vers -productVersion

# Enforce strict Gatekeeper policy (requires administrator)
sudo spctl --master-enable

# List applications with Full Disk Access via TCC database (read-only)
sudo sqlite3 /Library/Application\ Support/com.apple.TCC/TCC.db \
  "SELECT client, auth_value FROM access WHERE service='kTCCServiceSystemPolicyAllFiles';"