On August 6, 2026, Apple shipped an emergency, out-of-band fix for CVE-2026-65400, an authentication issue in screensharingd, the daemon behind Screen Sharing, macOS's built-in remote desktop service that listens on TCP port 5900. Apple's advisory describes an attacker who could reach the service over the network and authenticate without valid credentials, then read and write files as root—enough to achieve full remote code execution.