CVE-2025-31258 is a vulnerability identified in Apple macOS, specifically allowing an application to potentially break out of its sandbox environment. The sandbox is a critical security mechanism designed to isolate applications, restricting their access to system resources and user data, thereby limiting the potential damage from malicious or compromised apps. This vulnerability stems from improper access control (CWE-284), where an app can bypass sandbox restrictions, potentially gaining unauthorized access to system resources or other apps' data. The issue was addressed by Apple through the removal of the vulnerable code and is fixed starting with macOS Sequoia 15.5. The CVSS v3.1 score is 6.5 (medium severity), with the vector indicating that the vulnerability can be exploited remotely without authentication or user interaction (AV:N/AC:L/PR:N/UI:N), impacting confidentiality and integrity but not availability. No known exploits are reported in the wild as of the publication date. The vulnerability affects unspecified versions prior to the patch, implying that all macOS versions before 15.5 could be vulnerable. Given the nature of sandbox escapes, successful exploitation could allow malicious apps to access sensitive data, escalate privileges, or perform unauthorized actions beyond their intended scope, undermining the security model of macOS applications.

For European organizations, this vulnerability poses a significant risk, especially for those relying heavily on macOS devices for sensitive operations, including government agencies, financial institutions, and enterprises in sectors like healthcare and technology. A sandbox escape could enable attackers to access confidential information, intellectual property, or user credentials stored on macOS systems. This could lead to data breaches, espionage, or disruption of business processes. Since the vulnerability does not require user interaction or authentication, it could be exploited by malicious apps distributed through third-party sources or potentially even through compromised legitimate applications. The medium severity rating suggests a moderate but tangible risk, particularly in environments where macOS is widely used and where strict data protection regulations such as GDPR apply. The absence of known exploits in the wild currently reduces immediate risk but does not eliminate the threat, especially as attackers may develop exploits following public disclosure.

European organizations should prioritize updating all macOS devices to version Sequoia 15.5 or later to ensure the vulnerability is patched. Beyond patching, organizations should enforce strict application control policies, such as using Apple’s notarization and Gatekeeper features to restrict app installations to trusted sources only. Implementing endpoint detection and response (EDR) solutions tailored for macOS can help detect anomalous behaviors indicative of sandbox escapes. Regular audits of installed applications and monitoring for unauthorized software can reduce exposure. Additionally, organizations should educate users about the risks of installing untrusted applications and maintain robust backup and incident response plans to mitigate potential impacts. For environments with high security requirements, consider deploying macOS devices with enhanced security configurations, such as System Integrity Protection (SIP) and mandatory access controls, to further limit the potential damage from sandbox escapes.