CVE-2025-43508: Apple macOS Information Disclosure Flaw

CVE-2025-43508 Overview

CVE-2025-43508 is an information disclosure vulnerability in Apple macOS caused by improper data redaction in system logs. A local application can read log entries that contain sensitive user data that should have been redacted. Apple addressed the issue by improving data redaction in macOS Tahoe 26.1.

The flaw is tracked under CWE-532: Insertion of Sensitive Information into Log File. Exploitation requires local access and low privileges, and impacts confidentiality of user data without affecting integrity or availability.

Critical Impact

A local app with standard user privileges can harvest sensitive user data from macOS log files prior to the Tahoe 26.1 update.

Affected Products

• Apple macOS 26.0
• Apple macOS versions prior to Tahoe 26.1
• Applications relying on macOS unified logging on affected versions

Discovery Timeline

• 2026-01-16 - CVE-2025-43508 published to the National Vulnerability Database
• 2026-01-27 - Last updated in NVD database

Technical Details for CVE-2025-43508

Vulnerability Analysis

The vulnerability resides in macOS logging components that write event data to the unified logging subsystem. Log messages intended to mask sensitive fields were emitted without applying the expected redaction. As a result, values that should appear as <private> placeholders were instead recorded in cleartext.

A local app reading accessible log streams can retrieve this residual sensitive data. Exploitation does not require user interaction, and the attack is constrained to local context. The information disclosed depends on which subsystem produced the log entry, but can include data attributable to the user session.

Apple resolved the issue by enforcing improved data redaction across the affected logging paths in macOS Tahoe 26.1. The fix ensures that fields marked private remain redacted before serialization to persistent log stores.

Root Cause

The root cause is a logging misconfiguration classified under CWE-532. Privacy qualifiers controlling redaction were not applied consistently, so sensitive values reached the log store in plaintext. This represents a sensitive information exposure rather than a memory safety defect.

Attack Vector

The attack vector is local. An attacker must execute code on the target macOS system as a standard user. Once running, the attacker's process queries the log subsystem using documented APIs such as OSLog or the log command line tool, then parses returned entries for unredacted sensitive content. No elevated privileges and no user interaction are required.

Because exploitation relies on standard log query interfaces, the activity blends with legitimate diagnostic workflows. Per Apple's advisory, see the Apple Support Document for vendor disclosure details.

Detection Methods for CVE-2025-43508

Indicators of Compromise

• Unexpected processes invoking log show, log stream, or OSLogStore APIs outside of administrative workflows
• Non-system binaries reading from /var/db/diagnostics/ or /var/db/uuidtext/ paths
• Sustained log enumeration activity from user-context applications without diagnostic justification

Detection Strategies

• Monitor process execution telemetry for invocations of the log utility by non-administrative users
• Alert on file access events targeting unified log storage directories from unsigned or non-Apple binaries
• Correlate log query activity with parent process lineage to identify scripted or automated harvesting

Monitoring Recommendations

• Inventory installed applications that hold the com.apple.developer.diagnostics or related diagnostic entitlements
• Audit endpoint detection telemetry for sequences of log access followed by network egress
• Track macOS version compliance and flag endpoints still running macOS 26.0 or earlier

How to Mitigate CVE-2025-43508

Immediate Actions Required

• Update affected endpoints to macOS Tahoe 26.1 or later as the primary remediation
• Inventory macOS endpoints currently on macOS 26.0 and prioritize them for patch deployment
• Review installed third-party applications for unnecessary log access behavior

Patch Information

Apple released the fix in macOS Tahoe 26.1 with improved data redaction logic. Refer to the Apple Support Document for the official advisory and release notes. No vendor-supplied workaround is documented; applying the update is the supported remediation.

Workarounds

• Restrict installation of untrusted applications until the macOS Tahoe 26.1 update is applied
• Limit standard user accounts from running arbitrary developer tooling that can query the log subsystem
• Rotate credentials or tokens that may have been written to logs on unpatched systems prior to update

# Verify macOS version and trigger software update
sw_vers -productVersion
sudo softwareupdate --install --all --restart