CVE-2025-43391 is a privacy-related vulnerability identified in Apple macOS and related operating systems, including iOS and iPadOS. The root cause lies in improper handling of temporary files by the operating system, which can allow a malicious or compromised application to access sensitive user data that should otherwise be protected. Temporary files often contain transient data that may include personal information or application-specific secrets. If these files are not securely managed—such as by incorrect permissions, residual data exposure, or improper cleanup—an attacker-controlled app can exploit this to read data belonging to other apps or the user. Apple has addressed this issue in macOS Sonoma 14.8.2, macOS Sequoia 15.7.2, and iOS/iPadOS 26.1 by improving the handling and isolation of temporary files, thereby preventing unauthorized access. The vulnerability was reserved in April 2025 and published in November 2025. There are no known exploits in the wild at the time of publication, but the nature of the vulnerability suggests that exploitation could be straightforward for apps with user-level privileges. Since the vulnerability affects confidentiality primarily, it poses a significant privacy risk, especially in environments where sensitive or regulated data is handled. The lack of a CVSS score necessitates a severity assessment based on impact and exploitability factors.

For European organizations, the primary impact of CVE-2025-43391 is the potential unauthorized disclosure of sensitive user data. This can include personal information, credentials, or proprietary data stored temporarily by applications. Such data leakage can lead to privacy violations, regulatory non-compliance (e.g., GDPR), reputational damage, and potential financial losses. Organizations relying on macOS for critical operations, especially in sectors like finance, healthcare, legal, and government, face heightened risks. The vulnerability could be exploited by malicious apps distributed through less controlled channels or via social engineering to gain user consent. Since the issue affects confidentiality without requiring elevated privileges or complex exploitation, the attack surface is broad. The absence of known exploits currently reduces immediate risk but does not eliminate the threat, especially as attackers may develop exploits post-disclosure. Additionally, organizations using macOS in multi-user environments or with shared devices are at increased risk of cross-user data leakage.

To mitigate CVE-2025-43391, European organizations should: 1) Immediately apply the security updates released by Apple for macOS Sonoma 14.8.2, macOS Sequoia 15.7.2, and iOS/iPadOS 26.1 to ensure the vulnerability is patched. 2) Enforce strict application installation policies, limiting apps to those from trusted sources such as the Apple App Store to reduce the risk of malicious apps exploiting this flaw. 3) Implement endpoint protection solutions that monitor and restrict unauthorized file access and suspicious app behavior, particularly focusing on temporary file directories. 4) Educate users about the risks of installing untrusted applications and the importance of timely OS updates. 5) For organizations with sensitive data, consider additional data encryption at rest and in use, and implement strict access controls and auditing on macOS devices. 6) Regularly review and harden macOS security configurations, including sandboxing and privacy settings, to minimize app permissions and exposure. 7) Monitor security advisories from Apple and threat intelligence sources for any emerging exploit activity related to this vulnerability.