CVE-2025-43406 is a logic-based vulnerability identified in Apple macOS, specifically addressed in the macOS Tahoe 26.1 update. The vulnerability arises from a logic flaw that allowed applications with limited privileges to bypass certain OS-imposed restrictions and gain unauthorized access to sensitive user data. The issue is categorized under CWE-497, which relates to the exposure of sensitive information to an unauthorized actor. The CVSS v3.1 base score is 5.5, indicating a medium severity level. The vector string (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N) reveals that the attack requires local access (AV:L), low attack complexity (AC:L), and low privileges (PR:L), but no user interaction (UI:N). The scope remains unchanged (S:U), and the impact is high on confidentiality (C:H) but none on integrity (I:N) or availability (A:N). This means an attacker with local access and limited privileges could exploit this flaw to read sensitive data without altering or disrupting system operations. The vulnerability does not require user interaction, increasing the risk of stealthy data breaches. Although no exploits are known in the wild, the potential for sensitive data exposure makes it a significant concern. The affected macOS versions are unspecified, but the fix is included in macOS Tahoe 26.1, emphasizing the importance of timely patching. The lack of patch links suggests users should rely on official Apple update channels. This vulnerability highlights the importance of robust access control and logic validation within operating systems to prevent unauthorized data access by local applications.

For European organizations, the primary impact of CVE-2025-43406 is the potential unauthorized disclosure of sensitive user data on macOS devices. This could include personal information, credentials, or corporate data stored or accessible on affected systems. Confidentiality breaches can lead to privacy violations, regulatory non-compliance (e.g., GDPR), reputational damage, and potential financial losses. Since the vulnerability requires local access and low privileges, it poses a risk from insider threats, compromised user accounts, or malicious software already present on endpoints. The absence of integrity and availability impacts means system operations remain stable, but data confidentiality is compromised. Organizations with macOS-heavy environments, such as creative industries, software development firms, and enterprises using Apple hardware, are particularly at risk. The medium severity rating suggests the threat is significant but not critical, allowing some time for remediation. However, failure to patch could facilitate lateral movement or data exfiltration in targeted attacks. European entities must consider this vulnerability in their endpoint security and data protection strategies to mitigate potential breaches and comply with data protection laws.

1. Immediately update all macOS systems to macOS Tahoe 26.1 or later, as this version contains the fix for CVE-2025-43406. 2. Restrict installation of applications to trusted sources such as the Apple App Store or enterprise-approved software repositories to reduce the risk of malicious local apps exploiting this vulnerability. 3. Implement strict endpoint security controls, including application whitelisting and behavior monitoring, to detect and prevent unauthorized access attempts to sensitive data by local applications. 4. Enforce the principle of least privilege for user accounts and applications, minimizing the number of users and apps with local privileges that could exploit this flaw. 5. Conduct regular audits of local user activities and application permissions to identify anomalous access patterns indicative of exploitation attempts. 6. Educate users about the risks of installing untrusted software and the importance of reporting suspicious system behavior. 7. Integrate macOS vulnerability management into the broader organizational patch management and risk assessment processes to ensure timely updates. 8. Consider deploying endpoint detection and response (EDR) solutions capable of identifying exploitation techniques related to local privilege misuse and data access. 9. For highly sensitive environments, implement data encryption and access controls at the application and file system levels to add layers of protection beyond OS-level controls.