CVE-2026-28839: Apple macOS Information Disclosure Flaw

CVE-2026-28839 Overview

CVE-2026-28839 is an improper authorization vulnerability affecting multiple versions of Apple macOS. The vulnerability stems from insufficient access control checks that allow a malicious application to access sensitive user data without proper authorization. Apple addressed this security issue with improved validation checks in macOS Sequoia 15.7.5, macOS Sonoma 14.8.5, and macOS Tahoe 26.4.

Critical Impact

A malicious application running on an affected macOS system could bypass authorization controls and access sensitive user data, potentially compromising user privacy and exposing confidential information.

Affected Products

• Apple macOS Sequoia (versions prior to 15.7.5)
• Apple macOS Sonoma (versions prior to 14.8.5)
• Apple macOS Tahoe (versions prior to 26.4)

Discovery Timeline

• 2026-03-25 - CVE-2026-28839 published to NVD
• 2026-03-25 - Last updated in NVD database

Technical Details for CVE-2026-28839

Vulnerability Analysis

This vulnerability is classified under CWE-285 (Improper Authorization), indicating that the affected macOS components fail to properly verify whether an application has the necessary permissions before granting access to sensitive user data. The network attack vector suggests that the vulnerability could potentially be triggered through network-delivered applications or content.

The improper authorization flaw allows applications to circumvent the standard macOS permission model. While macOS implements a robust permission framework requiring explicit user consent for accessing sensitive data (such as contacts, calendars, photos, and location data), this vulnerability provides a mechanism for malicious apps to bypass these security controls.

Root Cause

The root cause of CVE-2026-28839 lies in insufficient validation checks within the macOS authorization subsystem. When applications request access to protected user data, the operating system's access control mechanisms failed to properly verify the legitimacy of these requests. Apple addressed this by implementing improved checks to ensure that authorization requests are properly validated before granting data access.

Attack Vector

The vulnerability can be exploited through a malicious application installed on the target macOS system. An attacker would need to convince a user to install and run a crafted application that exploits the improper authorization flaw. Once executed, the malicious app could:

1. Bypass macOS privacy protections without triggering permission dialogs
2. Silently access sensitive user data including personal files and application data
3. Exfiltrate collected information to attacker-controlled servers

The attack requires no user interaction beyond the initial application execution, making it particularly dangerous for users who inadvertently install malicious software.

Detection Methods for CVE-2026-28839

Indicators of Compromise

• Unexpected applications accessing sensitive data directories such as ~/Library/Application Support/, ~/Documents/, or protected system locations
• Unusual network connections from applications that should not require internet access
• System logs showing authorization requests from unrecognized or recently installed applications
• Privacy permission changes in System Preferences/System Settings without user initiation

Detection Strategies

• Monitor for applications accessing TCC (Transparency, Consent, and Control) protected resources without corresponding user permission grants
• Deploy endpoint detection solutions capable of identifying authorization bypass attempts on macOS systems
• Implement application allowlisting to prevent execution of untrusted applications
• Review system audit logs for unusual tccd (TCC daemon) activity patterns

Monitoring Recommendations

• Enable macOS Unified Logging and monitor for authorization-related events
• Configure alerts for applications accessing sensitive user data directories
• Deploy SentinelOne agents with macOS-specific behavioral detection capabilities
• Establish baseline application behavior and alert on deviations in data access patterns

How to Mitigate CVE-2026-28839

Immediate Actions Required

• Update all macOS systems to the patched versions: Sequoia 15.7.5, Sonoma 14.8.5, or Tahoe 26.4
• Audit recently installed applications and remove any untrusted or suspicious software
• Review Privacy & Security settings to verify application permissions are appropriate
• Enable automatic software updates to ensure timely installation of future security patches

Patch Information

Apple has released security updates addressing this vulnerability across three macOS versions. Organizations and users should apply these updates immediately:

• Apple Support Advisory #126794 - macOS Sequoia 15.7.5
• Apple Support Advisory #126795 - macOS Sonoma 14.8.5
• Apple Support Advisory #126796 - macOS Tahoe 26.4

Updates can be installed via System Preferences/System Settings > Software Update, or through enterprise management tools such as Jamf Pro or Apple Business Manager.

Workarounds

• Restrict application installations to only those from the Mac App Store or identified developers via Gatekeeper settings
• Implement strict application control policies using MDM solutions
• Limit user accounts to standard (non-administrator) privileges to reduce potential impact
• Monitor and restrict network access for applications that should not require connectivity

# Verify current macOS version
sw_vers -productVersion

# Check for available security updates
softwareupdate --list

# Install all available updates
sudo softwareupdate --install --all --restart