CVE-2026-20647 is a vulnerability identified in Apple macOS that allows an application to access sensitive user data improperly due to insufficient data protection controls. The vulnerability is classified under CWE-200, which relates to information exposure. The flaw permits an app with low privileges (no prior authentication required) to read sensitive data, potentially compromising user confidentiality. The CVSS v3.1 base score is 5.5 (medium), with the vector indicating local attack vector (AV:L), low attack complexity (AC:L), no privileges required (PR:N), user interaction required (UI:R), unchanged scope (S:U), high impact on confidentiality (C:H), and no impact on integrity or availability (I:N, A:N). The issue was resolved in macOS Tahoe 26.3 by enhancing data protection mechanisms to prevent unauthorized access. Although no exploits are known in the wild, the vulnerability poses a risk to user privacy and sensitive information. The affected versions are unspecified but presumably include macOS versions prior to 26.3. The vulnerability requires local access and some user interaction, limiting remote exploitation but still posing a threat in scenarios where malicious apps or users gain local access.

The primary impact of CVE-2026-20647 is the unauthorized disclosure of sensitive user data on affected macOS systems. This can lead to privacy violations, leakage of personal or corporate confidential information, and potential escalation of further attacks if sensitive credentials or data are exposed. Organizations relying on macOS devices for handling sensitive information, including enterprises, government agencies, and individuals, face risks of data breaches. Since the vulnerability does not affect system integrity or availability, it is less likely to cause system downtime but can undermine trust and compliance with data protection regulations. The requirement for local access and user interaction limits large-scale remote exploitation but does not eliminate insider threats or attacks via malicious applications installed by users. The absence of known exploits reduces immediate risk but does not preclude future exploitation attempts.

To mitigate CVE-2026-20647, organizations and users should promptly update affected macOS systems to version Tahoe 26.3 or later, where the vulnerability is fixed. Beyond patching, organizations should enforce strict application control policies to prevent installation or execution of untrusted or unsigned applications that could exploit this vulnerability. Employ endpoint protection solutions capable of detecting suspicious local activities and monitor for unusual access to sensitive data. Educate users about the risks of installing unknown applications and the importance of cautious user interaction. Implement least privilege principles to limit app permissions and use macOS security features such as System Integrity Protection (SIP) and sandboxing to reduce the attack surface. Regularly audit and review access to sensitive data to detect potential unauthorized access attempts. Finally, maintain up-to-date backups and incident response plans to address any data exposure incidents swiftly.