Microsoft promptly patched this week's 'wormable' Windows 10 flaw

Surface Laptop 3 15
Surface Laptop 3 15 (Image credit: Windows Central)

What you need to know

  • New cumulative updates are available for Windows 10 1909 and 1903.
  • The updates address the wormable vulnerability that was recently discussed in online leaks.
  • The bug didn't affect any versions of Windows 10 older than 1903.

Microsoft shipped out cumulative updates for Windows 10 version 1909 and Windows 10 version 1903 today. The updates address a vulnerability in the Microsoft Server Message Block 3.1.1 (SMBv3). The updates come just days after Microsoft's March Patch Tuesday updates.

The fix addresses a wormable vulnerability that we reported on earlier this week. Details of the vulnerability leaked online ahead of Patch Tuesday, and a fix for it was not included in the Patch Tuesday updates. Now, Microsoft has addressed the issue. Here's the highlight, as listed by a Microsoft support page:

  • Security update to the Microsoft Server Message Block 3.1.1 (SMBv3).

If you check the changelog from the support page, it lists the update to SMVv3 below Windows 10 version 1903 and not Windows 10 version 1909. That's because the two versions share a common core operating system and identical system files. Any changes listed in version 1903 are also available for version 1909.

Sean Endicott
News Writer and apps editor

Sean Endicott brings nearly a decade of experience covering Microsoft and Windows news to Windows Central. He joined our team in 2017 as an app reviewer and now heads up our day-to-day news coverage. If you have a news tip or an app to review, hit him up at