CVE-2026-20623: 
macOS vulnerability analysis and mitigation

CVE-2026-20623 is a permissions issue in Apple macOS Tahoe that allows a malicious app to access protected user data. The vulnerability was addressed by removing the vulnerable code, as disclosed in Apple's security advisory for macOS Tahoe 26.3, released February 11, 2026. It affects macOS Tahoe versions prior to 26.3 and was credited to an anonymous researcher. The CVSS v3.1 base score is 5.5 (Medium), reflecting a local attack vector with no privileges required but requiring user interaction (Apple Advisory).

The root cause is classified as CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor), stemming from a permissions issue in the Foundation component of macOS Tahoe. The vulnerability was remediated by removing the vulnerable code entirely rather than patching it, suggesting the affected code path had no legitimate use case that justified the access it permitted. Exploitation requires local access and some form of user interaction, limiting the attack surface to apps already running on the target system (Apple Advisory).

A malicious app running on an affected macOS Tahoe system could access protected user data without proper authorization. The confidentiality impact is rated High, while integrity and availability are unaffected, meaning exploitation results in unauthorized data disclosure rather than system compromise or data modification. The scope is limited to the local system, with no evidence of lateral movement potential (Apple Advisory).

Apple addressed CVE-2026-20623 in macOS Tahoe 26.3, released February 11, 2026, by removing the vulnerable code. Users and administrators should update affected macOS Tahoe systems to version 26.3 or later. No configuration-based workarounds have been published; upgrading to the patched release is the only recommended remediation (Apple Advisory).