CVE-2025-43478 is a use-after-free vulnerability identified in Apple macOS operating systems. This flaw arises from improper memory management where an application can reference memory after it has been freed, leading to undefined behavior. Specifically, this vulnerability can cause unexpected system termination, effectively a denial-of-service (DoS) condition. The issue was addressed by Apple through improved memory management in macOS Sequoia 15.7.2, Tahoe 26.1, and Sonoma 14.8.2. The vulnerability requires local privileges (low complexity) and does not require user interaction, meaning an attacker with limited access could trigger the system crash without needing to trick a user. The CVSS 3.1 base score is 5.5, reflecting a medium severity level, with attack vector local, low attack complexity, privileges required low, no user interaction, unchanged scope, and impact limited to availability (no confidentiality or integrity impact). There are no known exploits in the wild at the time of publication. The vulnerability is classified under CWE-416 (Use After Free), a common memory corruption issue that can lead to crashes or potentially more severe impacts if exploited differently. The affected versions are unspecified but presumed to be all versions prior to the patched releases. This vulnerability primarily poses a risk of denial-of-service by causing system crashes, which could disrupt operations on affected macOS systems.

For European organizations, the primary impact of CVE-2025-43478 is the potential for denial-of-service conditions on macOS devices. This could disrupt business operations, especially in environments where macOS systems are critical for daily workflows, such as creative industries, software development, and certain enterprise environments. Although the vulnerability does not compromise confidentiality or integrity, repeated or targeted exploitation could degrade system availability and productivity. Organizations relying on macOS for critical infrastructure or services may face operational interruptions. Additionally, environments with shared or multi-user macOS systems could see increased risk if a low-privileged user triggers the crash, affecting other users. The absence of known exploits reduces immediate risk, but the medium severity and ease of exploitation warrant timely patching to prevent future attacks. The impact is more pronounced in sectors with high macOS usage and where system uptime is critical.

European organizations should prioritize updating macOS systems to the patched versions: Sequoia 15.7.2, Tahoe 26.1, or Sonoma 14.8.2 as soon as possible. Implement strict access controls to limit local user privileges, reducing the risk of exploitation by low-privileged users. Employ endpoint protection solutions capable of detecting abnormal application behavior that could indicate attempts to exploit memory corruption vulnerabilities. Conduct regular audits of macOS devices to ensure compliance with patch management policies. For environments where immediate patching is not feasible, consider restricting access to vulnerable systems or isolating them from critical networks to minimize impact. Educate users and administrators about the risks of local privilege exploitation and encourage reporting of unusual system crashes. Monitor system logs for signs of repeated unexpected terminations that could indicate exploitation attempts. Finally, maintain up-to-date backups to ensure rapid recovery in case of denial-of-service incidents.