CVE-2025-31258 is a sandbox escape vulnerability in Apple macOS, identified as CWE-284 (Improper Access Control). The sandbox is a critical security feature that confines applications to a restricted environment, limiting their ability to access system resources and user data beyond their permissions. This vulnerability arises from a flaw in the sandbox implementation that allows a malicious or compromised app to break out of these restrictions. The exploit does not require any privileges or user interaction, making it easier for attackers to leverage. The vulnerability affects unspecified versions of macOS prior to Sequoia 15.5, where the vulnerable code was removed to fix the issue. The CVSS 3.1 score is 6.5, reflecting a medium severity with network attack vector, low attack complexity, no privileges required, and no user interaction needed. The impact primarily affects confidentiality and integrity, as the attacker could potentially access or modify data outside the sandbox, but does not affect availability. No known exploits are currently reported in the wild, but the vulnerability represents a significant risk if weaponized. Organizations relying on macOS should apply the update promptly to prevent potential exploitation.

For European organizations, this vulnerability poses a risk primarily to confidentiality and integrity of data on macOS systems. An attacker exploiting this flaw could bypass sandbox restrictions, potentially accessing sensitive information or modifying data that should be protected by sandbox boundaries. This could lead to data leakage, unauthorized data manipulation, or escalation of privileges within the compromised system. While availability is not directly impacted, the breach of sandbox isolation undermines the security model of macOS, increasing the risk of further attacks or lateral movement. Organizations in sectors such as finance, technology, and government that use macOS devices extensively could face targeted attacks exploiting this vulnerability. The lack of required privileges or user interaction lowers the barrier for exploitation, increasing the urgency for mitigation. However, the absence of known exploits in the wild suggests that immediate widespread attacks are not currently observed, but the risk remains significant.

European organizations should immediately verify the macOS versions deployed within their environment and prioritize upgrading to macOS Sequoia 15.5 or later, where the vulnerable code has been removed. Implement strict application control policies to limit the installation and execution of untrusted or unsigned applications that could exploit this vulnerability. Employ endpoint detection and response (EDR) solutions capable of monitoring for unusual sandbox escape behaviors or privilege escalation attempts. Regularly audit and restrict the use of developer tools or scripting environments that could be leveraged to exploit sandbox weaknesses. Educate users about the risks of installing unauthorized software and enforce least privilege principles to minimize potential attack surfaces. Additionally, maintain robust backup and recovery procedures to mitigate the impact of any potential compromise. Continuous monitoring of threat intelligence feeds for any emerging exploits related to CVE-2025-31258 is recommended to respond swiftly to new developments.