CVE-2025-31256 is a medium-severity vulnerability affecting Apple macOS systems, specifically related to the handling of the 'hot corner' feature. The hot corner functionality allows users to trigger certain actions by moving the mouse cursor to a screen corner. The vulnerability arises from improper cache management, which may cause the system to unexpectedly reveal deleted notes to the user when the hot corner is activated. This issue is classified under CWE-200 (Exposure of Sensitive Information) and impacts confidentiality by potentially exposing deleted user notes that should no longer be accessible. The vulnerability requires local access with low privileges (AV:L, PR:L) but does not require user interaction (UI:N) beyond triggering the hot corner. The scope is unchanged (S:U), meaning the impact is limited to the vulnerable system itself without affecting other systems. The CVSS v3.1 base score is 5.5, reflecting a medium severity level primarily due to the high confidentiality impact but limited attack vector and privileges required. Apple addressed this vulnerability in macOS Sequoia 15.5 by improving cache handling to prevent deleted notes from being displayed unexpectedly. No known exploits are currently reported in the wild, indicating that active exploitation is not yet observed. However, the exposure of deleted notes could lead to privacy breaches or leakage of sensitive information stored in the Notes app, which may include personal, corporate, or confidential data.

For European organizations, this vulnerability poses a privacy and confidentiality risk, especially for those using macOS devices in environments where sensitive or regulated data is handled. Deleted notes that are unexpectedly revealed could expose intellectual property, personal data protected under GDPR, or other confidential information. This could lead to compliance violations, reputational damage, and potential legal consequences. The impact is particularly relevant for sectors such as finance, healthcare, legal, and government agencies where data confidentiality is paramount. Although the vulnerability requires local access and low privileges, insider threats or compromised user accounts could exploit this to access deleted notes. The lack of requirement for user interaction beyond triggering the hot corner means an attacker with physical or remote access to a logged-in session could potentially retrieve sensitive information without alerting the user. However, since the vulnerability does not affect system integrity or availability, the primary concern remains data confidentiality.

European organizations should ensure that all macOS devices are updated to macOS Sequoia 15.5 or later, where this vulnerability is patched. IT administrators should enforce timely patch management policies and verify compliance across all Apple devices. Additionally, organizations should consider restricting physical and remote access to macOS systems to trusted personnel only, minimizing the risk of local exploitation. Implementing endpoint security solutions that monitor unusual user behavior or unauthorized access attempts can help detect potential exploitation attempts. Users should be educated about the risks of leaving devices unattended and the importance of locking screens when not in use. For highly sensitive environments, consider disabling or restricting the use of hot corners through system preferences or configuration profiles to reduce the attack surface. Finally, organizations should review data retention and deletion policies within the Notes app and ensure that sensitive information is securely deleted and not recoverable through caches or other means.