September's Windows 10 'Patch Tuesday' updates fix high CPU usage bug

Microsoft Surface Book 2
Microsoft Surface Book 2 (Image credit: Windows Central)

What you need to know

  • Microsoft's September "Patch Tuesday" updates are now available.
  • These updates focus on bug fixes and improvements for several Windows 10 releases.
  • Notably, the update for Windows 10 May 2019 Update PCs fixes the high CPU usage bug that sprung up this month.
  • The updates are available now via Windows Update.

Microsoft released a new batch of "Patch Tuesday" updates for Windows 10 PCs today. As with previous updates of this nature, these don't include any new features to check out. Rather, these updates focus on bug fixes and security updates across several Windows 10 releases.

For those running the Windows 10 May 2019 Update, you'll see KB4515384 (build 18362.356). Notably, this update includes a fix for an issue that causes high CPU usage from SearchUI.exe for some users. Here's a full look at what's included:

  • Provides protections against a new subclass of speculative execution side-channel vulnerabilities, known as Microarchitectural Data Sampling, for 32-Bit (x86) versions of Windows (CVE-2019-11091, CVE-2018-12126, CVE-2018-12127, CVE-2018-12130). Use the registry settings as described in the Windows Client and Windows Server articles. (These registry settings are enabled by default for Windows Client OS editions and Windows Server OS editions.)
  • Addresses an issue that causes high CPU usage from SearchUI.exe for a small number of users. This issue only occurs on devices that have disabled searching the web using Windows Desktop Search.
  • Security updates to Microsoft Edge, Internet Explorer, Microsoft Scripting Engine, Windows App Platform and Frameworks, Windows Input and Composition, Windows Media, Windows Fundamentals, Windows Authentication, Windows Cryptography, Windows Datacenter Networking, Windows Storage and Filesystems, Windows Wireless Networking, the Microsoft JET Database Engine, Windows Kernel, Windows Virtualization, and Windows Server.

Anyone running the October 2018 Update will see a similar set of fixes with KB4512578 (build 17763.737). Here's what's new:

  • Provides protections against a new subclass of speculative execution side-channel vulnerabilities, known as Microarchitectural Data Sampling, for 32-Bit (x86) versions of Windows (CVE-2019-11091, CVE-2018-12126, CVE-2018-12127, CVE-2018-12130). Use the registry settings as described in the Windows Client and Windows Server articles. (These registry settings are enabled by default for Windows Client OS editions and Windows Server OS editions.)
  • Security updates to Microsoft Edge, Internet Explorer, Microsoft Scripting Engine, Windows App Platform and Frameworks, Windows Input and Composition, Windows Fundamentals, Windows Authentication, Windows Cryptography, the Microsoft JET Database Engine, Windows Kernel, Windows Virtualization, and Windows Server.

The list of fixes for Windows 10 versions 1803 and earlier are largely the same as those provided for the October 2018 Update. For the full release notes, you can check out Microsoft's support site for more. Otherwise, hit up Windows Update to download this month's "Patch Tuesday" updates for your PC.

Dan Thorp-Lancaster

Dan Thorp-Lancaster is the former Editor-in-Chief of Windows Central. He began working with Windows Central, Android Central, and iMore as a news writer in 2014 and is obsessed with tech of all sorts. You can follow Dan on Twitter @DthorpL and Instagram @heyitsdtl