Microsoft Issues Security Fixes for 56 Flaws, Including Active Exploit and Two Zero-Days

Microsoft released security fixes for 56 vulnerabilities in December 2025, including one actively exploited vulnerability and two zero-day flaws. The security update addresses 3 Critical and 53 Important severity vulnerabilities across Windows platform products. Two vulnerabilities were publicly known at the time of release. The patches include fixes for 29 privilege escalation and 18 remote code execution vulnerabilities, representing a significant security update to close out 2025.