CVE-2026-20623
📋 TL;DR
A permissions vulnerability in macOS allowed applications to access protected user data they shouldn't have been able to access. This affects macOS systems running versions before Tahoe 26.3. The issue was resolved by removing the vulnerable code.
💻 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 or compromised applications could access sensitive user data including personal files, credentials, or other protected information stored on the system.
Likely Case
Applications with legitimate but limited permissions could inadvertently or intentionally access user data beyond their intended scope, potentially exposing personal information.
If Mitigated
With proper application sandboxing and user permission controls, the impact would be limited to data accessible by already-trusted applications.
🎯 Exploit Status
Exploitation requires a malicious or compromised application to be installed and running on the target system. No public exploit code is known.
🛠️ 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. Click General 3. Click Software Update 4. Install macOS Tahoe 26.3 update
🔧 Temporary Workarounds
Application Sandboxing Enforcement
macOSEnsure all applications run with appropriate sandboxing and permissions restrictions
🧯 If You Can't Patch
- Restrict installation of untrusted applications through MDM or parental controls
- Implement strict application allowlisting to prevent unauthorized software execution
🔍 How to Verify
Check if Vulnerable:
Check macOS version in System Settings > General > About. If version is earlier than Tahoe 26.3, system is vulnerable.Check Version:
sw_versVerify Fix Applied:
Verify macOS version shows Tahoe 26.3 or later in System Settings > General > About.📡 Detection & Monitoring
Log Indicators:
- Unusual file access patterns by applications
- Application permission escalation attempts
Network Indicators:
- None - this is a local privilege issue
SIEM Query:
process where (event_type="file_access" and process_name not in approved_apps_list) and file_path contains sensitive_directories