CVE-2025-43401

Root

Cause

CVE-2025-43401 is a denial-of-service (DoS) vulnerability in macOS's networking stack. The issue stems from insufficient validation of network input, which could be triggered by a remote attacker without requiring any prior authentication [1]. Apple fixed the bug by adding improved validation in the affected code in the affected component.

Exploitation

An attacker on the same network segment can send a specially crafted request to a vulnerable macOS system. No user interaction or local access is needed; the attack is entirely remote and pre-authentication, making it is network-based. Because the validation gap exists in core networking handling, a single malicious packet could be sufficient to crash or hang the service, leading to a DoS condition [1].

Impact

A successful exploit causes the targeted macOS device to become unresponsive or crash, denying service to legitimate users and potentially disrupting network connectivity. The vulnerability is rated High with a CVSS v3 base score of 7.5, reflecting the low complexity and network attack vector [1].

Mitigation

Apple addressed the issue in macOS Sequoia 15.7.2, macOS Sonoma 14.8.2, and macOS Tahoe 26.1, all released on November 3, 2025 [1][2][3]. Users are advised to apply the latest security updates. There are no known workarounds, and Apple does not disclose further details until an investigation is complete [1].