CVE-2026-20630 is a permissions-related vulnerability identified in Apple macOS, specifically addressed in macOS Tahoe 26.3. The issue stems from insufficient access control mechanisms (classified under CWE-277) that allow an application running with limited privileges (low privilege) to access protected user data that should normally be restricted. The vulnerability does not require user interaction to be exploited, but the attacker must have local access to the system. The CVSS v3.1 base score is 5.5, indicating a medium severity level, with the vector AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N, meaning the attack requires local access, low complexity, low privileges, no user interaction, unchanged scope, and results in high confidentiality impact without affecting integrity or availability. The vulnerability was reserved in November 2025 and published in February 2026. Although no known exploits are currently reported in the wild, the potential for unauthorized data access poses a significant privacy risk. The fix involves additional restrictions on permissions to prevent unauthorized data access by applications. This vulnerability highlights the importance of strict access control enforcement in operating systems to protect sensitive user data from local threats.

The primary impact of CVE-2026-20630 is the unauthorized disclosure of protected user data on affected macOS systems. Since the vulnerability allows an app with low privileges to bypass intended access controls, sensitive information such as personal files, credentials, or other protected data could be exposed. This compromises confidentiality but does not affect data integrity or system availability. Organizations relying on macOS devices, especially those handling sensitive or regulated data, face increased risk of data breaches or insider threats if this vulnerability is exploited. The requirement for local access limits remote exploitation but does not eliminate risk in environments where endpoint security is weak or where malicious insiders or compromised local accounts exist. The absence of user interaction lowers the barrier for exploitation once local access is gained. Overall, the vulnerability could facilitate data leakage, privacy violations, and potential compliance issues for organizations worldwide.

To mitigate CVE-2026-20630, organizations should prioritize updating all affected macOS systems to version Tahoe 26.3 or later, where the vulnerability is patched with enhanced permission restrictions. Beyond patching, organizations should enforce strict endpoint security policies to limit local access to trusted users only, including the use of strong authentication and account management practices. Employing application whitelisting can reduce the risk of malicious or unauthorized apps running with low privileges. Regular auditing of app permissions and monitoring for unusual local access attempts can help detect exploitation attempts early. Additionally, implementing data encryption and access controls at the file system level can provide defense-in-depth to protect sensitive data even if an app attempts unauthorized access. Organizations should also educate users about the risks of installing untrusted applications and maintain up-to-date security configurations to minimize attack surfaces.