CVE-2025-43266 is a medium-severity vulnerability affecting Apple macOS operating systems, specifically versions prior to macOS Sequoia 15.6, macOS Sonoma 14.7.7, and macOS Ventura 13.7.7 where the issue has been addressed. The vulnerability arises from a permissions issue that allows an application to potentially break out of its sandbox environment. Sandboxing is a critical security mechanism in macOS designed to isolate applications and restrict their access to system resources and user data, thereby limiting the potential damage from malicious or compromised apps. The flaw corresponds to CWE-732, which relates to incorrect permission assignment or enforcement. Exploiting this vulnerability does not require user interaction or elevated privileges (no authentication needed), and the attack vector is local (AV:L), meaning the attacker must have the ability to run code on the affected system. The CVSS v3.1 score is 5.1 (medium severity), reflecting limited confidentiality and integrity impact but no availability impact. Specifically, an attacker could leverage this flaw to escape the sandbox restrictions, potentially accessing or modifying data outside the app's intended scope. However, the vulnerability does not allow full system compromise or denial of service. No known exploits are currently reported in the wild, and Apple has released patches in recent macOS updates to mitigate this issue.

For European organizations, this vulnerability poses a moderate risk primarily to environments where macOS is widely used, such as creative industries, software development firms, and enterprises with Apple hardware deployments. The ability for an app to escape sandbox restrictions could lead to unauthorized access to sensitive data or modification of files beyond the app’s scope, undermining data confidentiality and integrity. While the vulnerability does not allow remote exploitation, insider threats or malicious apps installed by users could exploit it to escalate privileges or bypass security controls. This could facilitate lateral movement or data exfiltration within corporate networks. Organizations handling sensitive personal data under GDPR must be particularly cautious, as any unauthorized data access could lead to compliance violations and significant fines. The lack of known exploits reduces immediate risk, but the medium severity and potential for sandbox escape warrant timely patching and monitoring.

European organizations should prioritize updating all macOS systems to the fixed versions: macOS Sequoia 15.6, macOS Sonoma 14.7.7, or macOS Ventura 13.7.7. Beyond patching, organizations should enforce strict application control policies to limit the installation of untrusted or unsigned applications, reducing the risk of malicious apps exploiting this vulnerability. Employing endpoint detection and response (EDR) solutions that monitor for anomalous behavior indicative of sandbox escape attempts can enhance detection capabilities. Regular audits of installed applications and sandbox configurations can help identify potential security gaps. Additionally, educating users about the risks of installing unauthorized software and maintaining least privilege principles for user accounts will further reduce exploitation likelihood. For environments with sensitive data, consider deploying macOS security features such as System Integrity Protection (SIP) and enabling full disk encryption to mitigate the impact of any potential breach.