CVE-2026-28818: Apple macOS Information Disclosure Flaw

CVE-2026-28818 Overview

CVE-2026-28818 is an information disclosure vulnerability in Apple macOS caused by a logging issue with insufficient data redaction. The flaw allows an application to access sensitive user data that should have been protected through proper log sanitization. Apple addressed this vulnerability by implementing improved data redaction mechanisms in the affected logging components.

Critical Impact

Applications running on vulnerable macOS versions may be able to access and exfiltrate sensitive user data through improper log redaction, potentially exposing private information to unauthorized parties.

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-2026-28818 published to NVD
• 2026-03-25 - Last updated in NVD database

Technical Details for CVE-2026-28818

Vulnerability Analysis

This vulnerability stems from improper access control (CWE-284) within macOS logging subsystems. When applications generate logs or access system log files, sensitive user data that should have been redacted was instead being stored in a readable format. This creates an opportunity for malicious applications to harvest sensitive information by parsing log entries that contain unredacted user data.

The vulnerability affects the data redaction mechanisms that are supposed to sanitize logs before they are written to disk or made accessible to applications. When these protections fail, information that users expect to be private—such as credentials, personal identifiers, or activity details—may be exposed to any application with log reading capabilities.

Root Cause

The root cause is inadequate data redaction in the macOS logging framework. Log entries containing sensitive user information were not properly sanitized before being persisted, allowing applications with appropriate log access permissions to read data that should have been masked or removed entirely. This represents a failure in the defense-in-depth approach to protecting user privacy through log sanitization.

Attack Vector

The attack vector for CVE-2026-28818 is network-accessible and requires no user interaction or special privileges. An attacker would need to deploy a malicious application on the target macOS system. Once installed, the application could systematically access log files or log streams to extract sensitive user data that was improperly redacted.

The attack scenario involves:

1. A malicious application is installed on the target macOS system
2. The application accesses system or application logs through standard APIs
3. Due to the improper redaction, sensitive user data is readable within the log entries
4. The attacker exfiltrates the harvested sensitive information

No verified code examples are available for this vulnerability. The issue manifests in how the macOS logging subsystem handles sensitive data redaction. For complete technical details on the logging mechanisms affected, refer to the Apple Support Document #126794 and related security advisories.

Detection Methods for CVE-2026-28818

Indicators of Compromise

• Unusual application access patterns to system log directories such as /var/log/ or unified logging databases
• Applications querying the log command or Unified Logging APIs at abnormally high frequencies
• Unexpected network traffic following log access operations, indicating potential data exfiltration

Detection Strategies

• Monitor for applications accessing sensitive log files or directories outside of normal system administration patterns
• Implement application behavior analysis to detect log harvesting activities
• Deploy endpoint detection solutions that can identify suspicious log enumeration and data collection behaviors

Monitoring Recommendations

• Enable comprehensive logging of file system access to log directories and unified logging databases
• Configure SentinelOne Singularity platform to monitor for suspicious log access patterns on macOS endpoints
• Establish baseline application behavior to identify anomalous log access activity

How to Mitigate CVE-2026-28818

Immediate Actions Required

• Update macOS Sequoia to version 15.7.5 or later immediately
• Update macOS Sonoma to version 14.8.5 or later immediately
• Update macOS Tahoe to version 26.4 or later immediately
• Review installed applications and remove any untrusted or unnecessary software

Patch Information

Apple has released security updates that address this vulnerability by implementing improved data redaction in the logging framework. The patches are available through the following resources:

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

Organizations should apply these updates through standard macOS update mechanisms or MDM solutions.

Workarounds

• Restrict application installations to only trusted and verified software from the Mac App Store or identified developers
• Implement application sandboxing policies to limit log file access for non-essential applications
• Review and restrict file system permissions on sensitive log directories where possible

# Check current macOS version to verify patching status
sw_vers -productVersion

# Verify system updates are available and install security patches
softwareupdate --list
softwareupdate --install --all