CVE-2026-20629
📋 TL;DR
This macOS vulnerability allows applications to access sensitive user data through improper handling of temporary files. It affects macOS systems before version 26.3. The issue could expose personal information stored in temporary locations to unauthorized applications.
💻 Affected Systems
- macOS
📦 What is this software?
Macos by Apple
macOS is Apple's desktop and laptop operating system powering Mac computers used by millions of professionals, developers, creative professionals, and enterprise users worldwide. Built on a Unix foundation with the Darwin kernel and modern Cocoa frameworks, macOS delivers a seamless ecosystem integr...
Learn more about Macos →⚠️ Risk & Real-World Impact
Worst Case
Malicious applications could access and exfiltrate sensitive user data including documents, credentials, or personal information stored in temporary files.
Likely Case
Applications with legitimate permissions could inadvertently access temporary files containing sensitive data from other applications or user sessions.
If Mitigated
With proper application sandboxing and file permission controls, the risk is limited to applications already granted file system access.
🎯 Exploit Status
Exploitation requires a malicious or compromised application to be installed and executed on the target system. No remote exploitation vector exists.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: macOS Tahoe 26.3
Vendor Advisory: https://support.apple.com/en-us/126348
Restart Required: No
Instructions:
1. Open System Settings 2. Navigate to General > Software Update 3. Install macOS Tahoe 26.3 update 4. Follow on-screen instructions to complete installation
🔧 Temporary Workarounds
Restrict application installations
macOSOnly install applications from trusted sources and the Mac App Store to reduce risk of malicious applications exploiting this vulnerability.
Enable FileVault encryption
macOSFull disk encryption helps protect sensitive data even if temporary files are accessed.
sudo fdesetup enable
🧯 If You Can't Patch
- Implement strict application control policies to limit which applications can run on affected systems
- Regularly clear temporary files using disk cleanup utilities or manual deletion
🔍 How to Verify
Check if Vulnerable:
Check macOS version in System Settings > General > About. If version is earlier than 26.3, the system is vulnerable.Check Version:
sw_versVerify Fix Applied:
Verify macOS version shows 26.3 or later in System Settings > General > About.📡 Detection & Monitoring
Log Indicators:
- Unusual file access patterns in temporary directories
- Multiple applications accessing the same temporary files
Network Indicators:
- Unexpected outbound connections following file access to temporary directories
SIEM Query:
source="macos" AND (event_type="file_access" AND file_path CONTAINS "/tmp/" OR file_path CONTAINS "/var/tmp/")