Update Windows urgently: 159 security vulnerabilities are fixed in the latest patch

The first Patch Tuesday of 2025, stamped KB5050009, is available in Windows Update on Windows devices. And, the least we can say is that Microsoft didn't do things by halves with this security update. The year has barely started yet it is difficult to imagine a next monthly security update going beyond the content of this one. No less than 159 security vulnerabilities, a much higher value than that displayed for many months, have been patched, including several critical ones.

A patch that doesn't fit with the back of the dead hand

First of all, three new zero-day flaws already exploited (CVE-2025-21333, CVE-2025-21334 and CVE-2025-21335) concern a component of the NT kernel of Windows Hyper-V. If exploited, these flaws can allow attackers to elevate their privileges within the system. To our colleagues at ClubicSatnam Narang, security researcher at Tenable, explains: “The vulnerabilities are found in a component that manages communication between virtual machines and the host operating system.“

Five other zero-day vulnerabilities already revealed (in Windows App Package Installer, Windows Themes and Microsoft Access) are also fixed with this KB5050009 update. Other critical vulnerabilities have been fixed, including one in Windows OLE (CVE-2025-21298) and two in Remote Desktop (CVE-2025-21297 and CVE-2025-21309).

Microsoft, however, notes some problems with this update. One of them prevents ARM players from Roblox to use the title unless you download it directly from the official website.

AI as reinforcement for security?

Concerning these numerous flaws discovered, Satnam Narang specifies: “What makes these vulnerabilities particularly interesting is that they were apparently discovered using AI.“Last December, unpatched.ai already discovered the CVE-2024-49142 flaw using artificial intelligence.

While waiting to know whether AI will be our salvation or our doom in the field of computer security, don't delay launching Windows Update to take advantage of the KB5050009 update.