CVE-2025-43406 is a logic vulnerability identified in Apple macOS that allows an application to access sensitive user data improperly due to insufficient enforcement of access restrictions. The vulnerability stems from a flaw in the operating system's logic that governs data access permissions, enabling an app to bypass intended security controls. The exact mechanism of exploitation is not detailed, but it likely involves the app exploiting a design or implementation oversight in how macOS enforces data access policies. Apple addressed this issue in the macOS Tahoe 26.1 release by improving these restrictions to prevent unauthorized data access. No specific affected versions were enumerated, but the vulnerability was reserved in April 2025 and published in December 2025. There are no known exploits in the wild at this time, indicating that active exploitation has not been observed or reported. The lack of a CVSS score requires an independent severity assessment, which considers the potential impact on confidentiality, the ease of exploitation (likely requiring an app to be installed and run), and the scope of affected systems (all macOS users prior to the patch). Since the vulnerability allows unauthorized access to sensitive user data, it poses a significant privacy risk and could lead to data breaches if exploited. The vulnerability does not appear to require user interaction beyond app installation and execution, which could be facilitated by social engineering or malicious app distribution. This vulnerability is particularly relevant for organizations and individuals relying on macOS for sensitive operations, as it undermines the confidentiality guarantees of the platform.

The primary impact of CVE-2025-43406 is the unauthorized disclosure of sensitive user data on macOS systems. For European organizations, this could lead to breaches of personal data protected under GDPR, resulting in legal penalties, reputational damage, and loss of customer trust. Sensitive data exposure could include personal identifiers, corporate intellectual property, or confidential communications, depending on what data the vulnerable logic controls access to. Organizations in finance, healthcare, legal, and government sectors are especially at risk due to the high value of their data. The vulnerability could also facilitate further attacks if sensitive credentials or tokens are accessed, enabling lateral movement or privilege escalation. Since macOS is widely used in European enterprises, especially in creative industries, technology firms, and executive environments, the scope of impact is broad. The absence of known exploits currently reduces immediate risk but does not eliminate the threat, as attackers may develop exploits once the vulnerability details are public. Failure to patch promptly could expose organizations to targeted attacks or opportunistic malware leveraging this flaw to harvest data stealthily.

To mitigate CVE-2025-43406, European organizations should prioritize updating all macOS devices to version Tahoe 26.1 or later, which contains the fix for this vulnerability. IT departments should enforce strict patch management policies to ensure timely deployment of security updates. Additionally, organizations should audit installed applications and restrict app installation to trusted sources, such as the Apple App Store or enterprise-approved software repositories, to reduce the risk of malicious apps exploiting this flaw. Implementing application whitelisting and endpoint protection solutions that monitor app behavior can help detect and block unauthorized data access attempts. User education on the risks of installing untrusted software and phishing attacks that could deliver malicious apps is also critical. Organizations should review and tighten macOS privacy and security settings, including app permissions related to sensitive data access. Monitoring system logs and network traffic for unusual activity may help identify exploitation attempts early. Finally, organizations should prepare incident response plans to address potential data breaches resulting from exploitation of this vulnerability.