CVE-2026-28828: Apple macOS Information Disclosure Flaw

CVE-2026-28828 Overview

CVE-2026-28828 is a permissions vulnerability in Apple macOS that allows applications to improperly access sensitive user data. The vulnerability stems from improper access control (CWE-284) in vulnerable code that has since been removed by Apple in subsequent security updates. This flaw could allow a malicious application running on an affected system to bypass normal permission boundaries and access data that should be protected.

Critical Impact

A malicious or compromised application may be able to access sensitive user data without proper authorization, potentially exposing personal information, credentials, or confidential files stored on the affected macOS system.

Affected Products

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

Discovery Timeline

• 2026-03-25 - CVE-2026-28828 published to NVD
• 2026-03-25 - Last updated in NVD database

Technical Details for CVE-2026-28828

Vulnerability Analysis

This vulnerability is classified under CWE-284 (Improper Access Control), indicating that the affected macOS versions did not properly enforce access restrictions for certain operations. The flaw allows applications to circumvent the operating system's permission model, enabling unauthorized access to sensitive user data.

The attack vector is network-based, meaning an attacker could potentially deliver a malicious application remotely that, once executed on the target system, exploits the improper permissions to access protected data. The vulnerability does not require user interaction beyond the initial application execution and can be exploited without any authentication or special privileges on the system.

Apple addressed this vulnerability by removing the vulnerable code entirely, indicating that the flawed implementation could not be safely patched and required complete removal to ensure system security.

Root Cause

The root cause is improper access control in the affected macOS code paths. The vulnerable code failed to properly validate or enforce permission boundaries, allowing applications to access sensitive user data that should have been restricted. Apple's remediation approach of removing the vulnerable code entirely suggests the implementation was fundamentally flawed from a security perspective.

Attack Vector

The attack requires a malicious application to be executed on the target macOS system. This could occur through various delivery mechanisms:

1. A user downloads and runs a malicious application from an untrusted source
2. A previously trusted application is compromised and weaponized to exploit this vulnerability
3. A legitimate application is repackaged with malicious code to target this flaw

Once the malicious application is running, it can leverage the improper access control to read sensitive user data without the proper permission grants that macOS normally requires.

The vulnerability mechanism involves bypassing the permission enforcement layer in macOS. Detailed technical information can be found in Apple Security Advisory #126794, Apple Security Advisory #126795, and Apple Security Advisory #126796.

Detection Methods for CVE-2026-28828

Indicators of Compromise

• Unexpected application access to protected directories such as ~/Documents, ~/Desktop, or ~/Downloads without proper TCC (Transparency, Consent, and Control) prompts
• Unusual file read operations from applications that should not require access to sensitive user data
• System logs indicating permission violations or anomalous data access patterns from third-party applications

Detection Strategies

• Monitor macOS Unified Logs for TCC-related events indicating unauthorized data access attempts
• Implement endpoint detection rules to identify applications accessing sensitive directories without corresponding TCC database entries
• Deploy behavioral analysis to detect applications performing unexpected file system reconnaissance or bulk data reads

Monitoring Recommendations

• Enable advanced logging for file system access events on sensitive directories
• Configure SentinelOne agents to monitor for suspicious application behavior patterns consistent with data exfiltration
• Review installed applications regularly and verify their legitimacy through code signing verification

How to Mitigate CVE-2026-28828

Immediate Actions Required

• Update macOS Sequoia to version 15.7.5 or later
• Update macOS Sonoma to version 14.8.5 or later
• Update macOS Tahoe to version 26.4 or later
• Review recently installed applications for suspicious behavior or unknown origins

Patch Information

Apple has released security updates that address this vulnerability by removing the vulnerable code. Patches are available through the standard macOS Software Update mechanism or can be downloaded directly from Apple's security advisory pages:

• Apple Security Advisory #126794
• Apple Security Advisory #126795
• Apple Security Advisory #126796

Workarounds

• Restrict application installations to the Mac App Store or verified developers with valid code signatures until patches can be applied
• Review and revoke unnecessary application permissions in System Preferences > Security & Privacy > Privacy
• Enable Gatekeeper to block applications from unidentified developers

# Verify Gatekeeper is enabled
spctl --status

# Enable Gatekeeper if disabled
sudo spctl --master-enable

# Check for pending macOS updates
softwareupdate --list