CVE-2025-43331 is a vulnerability identified in Apple macOS, specifically addressed in the macOS Tahoe 26 release. The root cause is a downgrade issue involving code-signing restrictions, which are security mechanisms designed to ensure that only trusted applications can access protected user data. This vulnerability allows an application, without requiring user interaction or prior authentication, to bypass these restrictions and access protected user data. The attack vector is local (AV:L), meaning the attacker must have local access to the system, and the attack complexity is low (AC:L), indicating that exploitation does not require special conditions beyond local access. The vulnerability impacts confidentiality (C:L) but does not affect integrity or availability. The weakness is classified under CWE-862 (Missing Authorization), highlighting that the system fails to properly enforce authorization checks before granting access to sensitive data. No known exploits have been reported in the wild, suggesting limited or no active exploitation at this time. The vulnerability is mitigated by the additional code-signing restrictions introduced in macOS Tahoe 26, which prevent downgrade attacks that could circumvent these protections. Although the affected versions are unspecified, it is implied that versions prior to Tahoe 26 are vulnerable. This vulnerability underscores the importance of robust code-signing enforcement to protect user data on macOS systems.

For European organizations, the primary impact of CVE-2025-43331 is the potential unauthorized disclosure of protected user data on macOS devices. Since exploitation requires local access, the threat is most relevant in environments where attackers can gain physical or remote desktop access to macOS machines, such as through insider threats, compromised credentials, or lateral movement after initial breach. Confidentiality breaches could expose sensitive personal or corporate information, leading to privacy violations, regulatory non-compliance (e.g., GDPR), and reputational damage. The lack of impact on integrity and availability reduces the risk of data manipulation or service disruption. However, given the widespread use of macOS in European enterprises, especially in sectors like finance, technology, and creative industries, the vulnerability could be leveraged as part of multi-stage attacks. The absence of known exploits limits immediate risk but does not preclude future exploitation. Organizations relying on macOS systems should prioritize patching to prevent potential data leakage and maintain compliance with data protection regulations.

1. Upgrade all macOS systems to macOS Tahoe 26 or later, as this version includes the fix for the downgrade issue and enhanced code-signing restrictions. 2. Enforce strict code-signing policies and regularly audit installed applications to ensure only trusted and signed apps are permitted to run. 3. Limit local access to macOS devices by implementing strong physical security controls and restricting remote access through secure VPNs and multi-factor authentication. 4. Monitor macOS endpoints for unusual application behavior or unauthorized access attempts, using endpoint detection and response (EDR) tools tailored for macOS. 5. Educate users about the risks of installing untrusted software and the importance of reporting suspicious activity. 6. Implement least privilege principles to reduce the number of users with local access rights on macOS systems. 7. Regularly review and update security policies to incorporate the latest macOS security features and patches.