CVE-2025-43478 is a use-after-free vulnerability identified in Apple macOS operating systems, specifically addressed in macOS Sequoia 15.7.2, Sonoma 14.8.2, and Tahoe 26.1. The vulnerability stems from improper memory management where an application can reference memory after it has been freed, leading to undefined behavior. This flaw can be exploited by a local application with limited privileges (PR:L) without requiring user interaction (UI:N) to cause unexpected system termination, effectively resulting in a denial-of-service (DoS) condition. The vulnerability does not impact confidentiality or integrity but affects system availability (A:H). The CVSS vector indicates low attack complexity (AC:L) and local attack vector (AV:L), meaning the attacker must have local access but can exploit the flaw reliably. No known exploits have been reported in the wild, but the presence of this vulnerability poses a risk to system stability. The issue was resolved by Apple through improved memory management techniques in the specified macOS versions. The vulnerability is tracked under CWE-416 (Use After Free), a common memory corruption flaw that can lead to crashes or code execution in other contexts, though this instance is limited to causing system termination.

The primary impact of CVE-2025-43478 is on system availability, as exploitation can cause unexpected system termination leading to denial of service. For organizations, this could result in disruption of critical services running on affected macOS systems, potentially affecting productivity and operational continuity. Since the vulnerability requires local access and limited privileges, the risk is higher in environments where untrusted users or applications have local access to macOS devices. Although confidentiality and integrity are not directly affected, repeated exploitation could lead to operational instability and increased support costs. In sectors relying heavily on macOS platforms, such as creative industries, software development, and certain enterprise environments, this vulnerability could cause significant disruption if unpatched. The absence of known exploits reduces immediate threat but does not eliminate the risk, especially as attackers may develop exploits over time.

Organizations should prioritize updating affected macOS systems to the patched versions: macOS Sequoia 15.7.2, macOS Sonoma 14.8.2, and macOS Tahoe 26.1. Beyond patching, restrict local access to macOS devices to trusted users only, minimizing the risk of exploitation by unprivileged apps. Employ application whitelisting and endpoint protection solutions that can detect and block suspicious local activity. Regularly audit installed applications and remove or sandbox untrusted or unnecessary software to reduce attack surface. Implement strict user privilege management to limit the ability of applications to execute with elevated rights. Monitor system logs for unusual crashes or terminations that could indicate exploitation attempts. Educate users about the risks of running untrusted applications locally. Finally, maintain robust backup and recovery procedures to mitigate the impact of potential denial-of-service incidents.