CVE-2025-43380 is an out-of-bounds write vulnerability in Apple macOS that arises from improper input validation during file parsing. This vulnerability allows a local attacker with low privileges to cause an application to terminate unexpectedly by crafting a malicious file that triggers the out-of-bounds write condition. The issue affects multiple macOS versions prior to Sequoia 15.7.2, Tahoe 26.1, and Sonoma 14.8.2, which include the fix. The vulnerability is categorized under CWE-787, indicating that the root cause is writing data outside the bounds of allocated memory, which can corrupt memory and lead to application crashes. The CVSS v3.1 base score is 5.5 (medium severity) with vector AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H, meaning the attack requires local access with low privileges, no user interaction, and impacts availability only. No confidentiality or integrity impact is noted. There are no known exploits in the wild, suggesting limited active exploitation at this time. The vulnerability could be leveraged to disrupt critical applications or services running on macOS, causing denial of service conditions. The fix involves improved input validation to prevent out-of-bounds writes during file parsing.

The primary impact of CVE-2025-43380 is denial of service through unexpected application termination, which affects availability. While it does not compromise confidentiality or integrity, the ability to crash applications can disrupt business operations, especially if critical services or workflows rely on the affected macOS versions. Organizations with macOS endpoints used in sensitive or operational environments may experience interruptions or reduced productivity. Since exploitation requires local access with low privileges, the threat is more relevant in scenarios where attackers have some foothold on the system or where untrusted files are processed automatically. The absence of known exploits in the wild reduces immediate risk but does not eliminate the potential for future exploitation. Overall, the impact is moderate but could be significant in environments with high dependency on macOS applications.

To mitigate CVE-2025-43380, organizations should promptly apply the security updates released by Apple for macOS Sequoia 15.7.2, Tahoe 26.1, and Sonoma 14.8.2 or later. Beyond patching, organizations should implement strict controls on file sources and scanning mechanisms to prevent processing of untrusted or malformed files. Employ endpoint protection solutions capable of detecting anomalous application crashes or memory corruption behaviors. Limit local access privileges to reduce the risk of exploitation by low-privilege users. Regularly audit and monitor macOS systems for unusual application terminations or crashes that may indicate attempted exploitation. Additionally, educate users about the risks of opening files from untrusted sources. For environments with critical macOS applications, consider application whitelisting and sandboxing to contain potential impacts.