CVE-2026-28816: Apple macOS Path Traversal Vulnerability

CVE-2026-28816 Overview

CVE-2026-28816 is a path traversal vulnerability (CWE-22) in Apple macOS that allows applications to delete files for which they do not have permission. The flaw stems from improper path validation in the operating system's file handling mechanisms, enabling malicious or compromised applications to bypass file system permission checks and delete arbitrary files.

Critical Impact

This vulnerability allows unauthorized file deletion, potentially enabling data destruction, system instability, or privilege escalation through removal of security-critical files.

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-2026-28816 published to NVD
• 2026-03-26 - Last updated in NVD database

Technical Details for CVE-2026-28816

Vulnerability Analysis

This vulnerability is classified as a path traversal issue (CWE-22: Improper Limitation of a Pathname to a Restricted Directory). The flaw exists in macOS's path handling mechanisms, where insufficient validation of file paths allows applications to reference and delete files outside their authorized scope.

The attack requires local access to the system, meaning an attacker must have the ability to execute an application on the target machine. No user interaction is required for exploitation, and the attacker does not need elevated privileges to trigger the vulnerability. The primary impact is to data integrity, as unauthorized file deletion can corrupt or destroy user data, application files, or potentially system components.

This type of vulnerability is particularly concerning in multi-user environments or systems where applications are sandboxed, as it undermines the fundamental file system access controls that protect sensitive data from unauthorized modification.

Root Cause

The root cause is improper path validation in macOS's file handling subsystem. When an application requests file operations, the operating system fails to adequately canonicalize and validate the provided file paths. This allows specially crafted path strings containing directory traversal sequences or symbolic link manipulations to bypass permission checks, ultimately allowing deletion of files that should be protected from the requesting application.

Attack Vector

The attack vector is local, requiring an attacker to execute a malicious application on the target macOS system. The exploitation scenario involves:

1. An attacker crafts or deploys a malicious application on the victim's macOS system
2. The application constructs file paths using traversal techniques to reference files outside its authorized scope
3. The application issues delete operations against these crafted paths
4. Due to insufficient validation, macOS processes these delete requests without proper permission enforcement
5. Files are deleted regardless of the application's actual permissions

The vulnerability does not require privilege escalation or user interaction, making it exploitable by any application running on the system.

Detection Methods for CVE-2026-28816

Indicators of Compromise

• Unexpected file deletions in system directories or protected locations
• Application logs showing unusual file path operations with traversal sequences (e.g., ../, symbolic links)
• Missing configuration files, user data, or system components without user-initiated deletion
• Audit logs indicating file operations by applications accessing paths outside their sandboxed directories

Detection Strategies

• Enable macOS Unified Logging and monitor for file deletion events from applications accessing unexpected paths
• Implement file integrity monitoring (FIM) on critical system and user directories to detect unauthorized deletions
• Monitor for applications exhibiting unusual file system access patterns, particularly those referencing parent directories or symbolic links
• Deploy endpoint detection solutions that can identify path traversal attempts in file operations

Monitoring Recommendations

• Configure macOS audit policies to log all file deletion operations system-wide
• Implement real-time alerting on file deletions in protected system directories such as /System, /Library, and user home directories
• Regularly review application entitlements and sandbox configurations to ensure appropriate file system restrictions
• Use SentinelOne's behavioral AI to detect applications performing anomalous file system operations

How to Mitigate CVE-2026-28816

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 installed applications for signs of compromise or malicious behavior
• Verify critical system and user files have not been unexpectedly deleted

Patch Information

Apple has released security updates addressing this vulnerability across multiple macOS versions. Detailed patch information is available through Apple's official security advisories:

• Apple Security Update #126794 - macOS Sequoia 15.7.5
• Apple Security Update #126795 - macOS Sonoma 14.8.5
• Apple Security Update #126796 - macOS Tahoe 26.4

Workarounds

• Restrict application installations to trusted sources (Mac App Store, verified developers) to reduce exposure to malicious applications
• Enable macOS Gatekeeper and ensure it is configured to only allow applications from identified developers
• Implement Time Machine backups or alternative backup solutions to enable recovery from unauthorized file deletions
• Consider using application sandboxing and tightened file system permissions for sensitive directories until patches are applied

# Verify macOS version to confirm patch status
sw_vers -productVersion

# Enable additional file system auditing
sudo audit -c

# Check Gatekeeper status
spctl --status