Microsoft Patch Tuesday, December 2025 Edition

Microsoft Patch Tuesday for December 2025, published on 9 December 2025, fixes at least 56 security flaws across Windows and related software. The update includes one zero-day vulnerability, CVE-2025-62221, a privilege escalation flaw in the Windows Cloud Files Mini Filter Driver that affects Windows 10 and later, described as a core Windows component used by cloud applications.

Three flaws earning Microsoft’s most-dire “critical” rating are CVE-2025-62554 and CVE-2025-62557 in Microsoft Office, exploitable by merely viewing a booby-trapped email in the Preview Pane, and CVE-2025-62562 in Microsoft Outlook, though Redmond says the Preview Pane is not an attack vector for this one.

The article notes that, according to Microsoft, most likely to be exploited are non-critical privilege escalation bugs such as CVE-2025-62458 (Win32k), CVE-2025-62470 (Windows CLFS), CVE-2025-62472 (Win Remote Access Connection Manager), CVE-2025-59516 and CVE-2025-59517 (both Windows Storage VSP Driver).

It also highlights CVE-2025-64671, a remote code execution flaw in the Github Copilot Plugin for Jetbrains, with analysis from Kev Breen of Immersive, and CVE-2025-54100, a Powershell RCE on Windows Server 2008 and later, noted by security researchers and linked to the broader IDEsaster concerns; Satnam Narang at Tenable is quoted on the tendency for privilege escalation flaws to appear in incidents, and the roundup directs readers to SANS for a deeper breakdown. According to Satnam Narang at Tenable, this year marks the second consecutive year Microsoft patched over one thousand vulnerabilities.