CVE-2025-43261 is a logic flaw vulnerability in Apple macOS that allows an application to potentially escape 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. This vulnerability arises from insufficient or flawed checks in the sandbox enforcement logic, which an attacker could exploit to break out of the sandbox containment. Successful exploitation would enable a malicious app to gain elevated privileges or broader access beyond its intended restricted environment, potentially accessing sensitive system components, user data, or other applications. Apple has addressed this issue with improved validation checks in macOS Sequoia 15.6, macOS Sonoma 14.7.7, and macOS Ventura 13.7.7. However, the affected versions prior to these updates remain vulnerable. No CVSS score has been assigned yet, and there are no known exploits in the wild at the time of publication. The vulnerability was reserved in April 2025 and published in July 2025, indicating a recent discovery and disclosure. Given the nature of sandbox escapes, this vulnerability poses a significant risk to the integrity and confidentiality of affected systems, especially in environments where untrusted or third-party applications are run. The lack of a CVSS score and known exploits suggests that exploitation complexity may be moderate, but the impact could be severe if successfully leveraged.

For European organizations, this vulnerability could have serious implications, particularly for enterprises and government agencies relying on macOS devices for sensitive operations. A sandbox escape could allow attackers to bypass application-level restrictions, leading to unauthorized access to confidential data, intellectual property, or critical system components. This could facilitate further lateral movement within networks, privilege escalation, or deployment of persistent malware. Organizations in sectors such as finance, healthcare, and public administration, which often use macOS for secure workflows, may face increased risk of data breaches or operational disruption. Additionally, the vulnerability could undermine trust in macOS security models, potentially impacting compliance with data protection regulations like GDPR if personal data is compromised. Since no known exploits are currently reported, the immediate threat level is moderate, but the potential for future exploitation necessitates proactive mitigation.

European organizations should prioritize updating all macOS devices to the patched 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, limiting installation and execution of untrusted or unsigned applications to reduce exposure. Employing endpoint detection and response (EDR) solutions capable of monitoring for anomalous sandbox escape behaviors can provide early detection of exploitation attempts. Network segmentation should be implemented to contain potential lateral movement from compromised macOS endpoints. Additionally, organizations should conduct regular security audits and user training to minimize the risk of social engineering attacks that could deliver malicious apps. For environments requiring high security, consider deploying macOS devices with enhanced security configurations, such as System Integrity Protection (SIP) and mandatory code signing enforcement. Finally, maintain up-to-date inventories of macOS assets and ensure rapid deployment of security updates to reduce the window of vulnerability.