CVE-2026-28829 is a permissions-related vulnerability in Apple macOS that allows an application to modify protected parts of the file system. The root cause is an improper permissions configuration (CWE-732) that fails to adequately restrict access to critical system files or directories. Exploitation requires local access and user interaction, as the attacker must run a malicious app that leverages this flaw to alter protected file system areas. The vulnerability does not compromise confidentiality or availability but poses a significant risk to system integrity, as unauthorized modifications to protected files can lead to privilege escalation, persistence mechanisms, or tampering with security controls. Apple addressed this issue in macOS Sequoia 15.7.5, Sonoma 14.8.5, and Tahoe 26.4 by implementing additional restrictions on file system permissions. The CVSS v3.1 score of 5.5 reflects a medium severity, considering the low attack vector (local), low complexity, no privileges required, but requiring user interaction. No public exploits or active exploitation have been reported, but the vulnerability remains a concern for environments where untrusted applications may be executed. This vulnerability underscores the criticality of enforcing strict access controls on system files to prevent unauthorized modifications that could undermine system security.

The primary impact of CVE-2026-28829 is on the integrity of affected macOS systems. An attacker who successfully exploits this vulnerability can modify protected parts of the file system, potentially leading to unauthorized changes in system behavior, installation of persistent malware, or bypassing security mechanisms. Although confidentiality and availability are not directly affected, the integrity compromise can indirectly facilitate further attacks, including privilege escalation or data manipulation. Organizations relying on macOS for critical operations, especially those with sensitive data or regulatory requirements, face increased risk of system compromise and operational disruption. The requirement for user interaction limits remote exploitation but does not eliminate risk, particularly in environments where users may inadvertently run malicious applications. The absence of known exploits reduces immediate threat but does not preclude future exploitation attempts. Overall, this vulnerability can undermine trust in system integrity and complicate incident response and forensic investigations if exploited.

To mitigate CVE-2026-28829, organizations should promptly apply the security updates provided by Apple in macOS Sequoia 15.7.5, Sonoma 14.8.5, and Tahoe 26.4 or later versions. Beyond patching, organizations should enforce strict application control policies, such as using Apple’s Gatekeeper and notarization requirements to restrict the execution of untrusted or unsigned applications. Employing endpoint protection solutions that monitor file system changes can help detect unauthorized modifications. User education is critical to reduce the risk of running malicious apps, emphasizing caution with downloads and attachments. Additionally, implementing least privilege principles for user accounts and restricting local administrative rights can limit the potential impact. Regular auditing of file system permissions and integrity checks can help identify anomalies early. For high-security environments, consider deploying macOS security features like System Integrity Protection (SIP) and Endpoint Security Framework to further harden the system against unauthorized changes.