CVE-2026-20618: 
macOS vulnerability analysis and mitigation

CVE-2026-20618 is an insecure temporary file handling vulnerability in Apple macOS Tahoe (System Settings component) that allows a locally installed app to access user-sensitive data. It was disclosed on February 11, 2026, as part of Apple's security advisory for macOS Tahoe 26.3, and affects macOS Tahoe versions prior to 26.3. The vulnerability was discovered by researcher Asaf Cohen. It carries a CVSS v3.1 base score of 5.5 (Medium) (Apple Advisory).

The root cause is classified as CWE-377 (Insecure Temporary File), where the System Settings component improperly handles temporary files in a way that exposes user-sensitive data to other applications. Apple addressed the issue with improved handling of temporary files. Exploitation requires local access and low privileges, with no user interaction needed, making it accessible to any app running on the affected system (Apple Advisory).

Successful exploitation allows a malicious app to read user-sensitive data that should be protected, resulting in a high confidentiality impact. There is no integrity or availability impact. The attack is limited to the local system scope, but sensitive personal data accessible through System Settings — such as account credentials, configuration data, or personal preferences — could be exposed to an unprivileged app (Apple Advisory).

Apple has released a patch in macOS Tahoe 26.3, which addresses the issue with improved handling of temporary files. Users and administrators should update to macOS Tahoe 26.3 or later as soon as possible. No configuration-based workaround has been published; upgrading is the only recommended remediation (Apple Advisory).