August 'Patch Tuesday' updates now rolling out

It's the second Tuesday of August, which means it's time for another batch of "Patch Tuesday" updates from Microsoft. As with previous Patch Tuesday releases, these cumulative updates don't contain any new features. Rather, you'll find a slew of fixes on board for supported versions of Windows.

If you're on Microsoft's latest Windows 10 release, the April 2018 Update, you'll find today's fixes in KB4343909 (build 17134.228). This release also packs updates for Microsoft HoloLens. Here's a look at what's new:

• Provides protections against a new speculative execution side-channel vulnerability known as L1 Terminal Fault (L1TF) that affects Intel® Core® processors and Intel® Xeon® processors (CVE-2018-3620 and CVE-2018-3646). Make sure previous OS protections against Spectre Variant 2 and Meltdown vulnerabilities are enabled using the registry settings outlined in the Windows Client and Windows Server guidance KB articles. (These registry settings are enabled by default for Windows Client OS editions, but disabled by default for Windows Server OS editions.)
• Addresses an issue that causes high CPU usage that results in performance degradation on some systems with Family 15h and 16h AMD processors. This issue occurs after installing the June 2018 or July 2018 Windows updates from Microsoft and the AMD microcode updates that address Spectre Variant 2 (CVE-2017-5715 – Branch Target Injection).
• Addresses an issue that prevents apps from receiving mesh updates after resuming. This issue occurs for apps that use Spatial Mapping mesh data and participate in the Sleep or Resume cycle. Ensures that Internet Explorer and Microsoft Edge support the preload="none" tag.
• Addresses an issue that prevents some applications running on HoloLens, such as Remote Assistance, from authenticating after upgrading from Windows 10, version 1607, to Windows 10, version 1803.
• Addresses an issue that significantly reduced battery life after upgrading to Windows 10, version 1803. Addresses an issue that causes Device Guard to block some ieframe.dll class IDs after installing the May 2018 Cumulative Update. Addresses a vulnerability related to the Export-Modulemember() function when used with a wildcard (*) and a dot-sourcing script. After installing this update, existing modules on devices that have Device Guard enabled will intentionally fail. The exception error is "This module uses the dot-source operator while exporting functions using wildcard characters, and this is disallowed when the system is under application verification enforcement." For more information, see https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-8200 and https://www.windowscentral.com/e?link=https%3A%2F%2Fclick.linksynergy.com%2Fdeeplink%3Fid%3DkXQk6%252AivFEQ%26mid%3D24542%26u1%3DUUwpUdUnU57966%26murl%3Dhttps%253A%252F%252Fwww.microsoft.com%252Fen-us%252F%253Fref%253Daka&token=RPOeV2k0

If you're still running a PC on the Fall Creators Update, you'll find a similarly short set of fixes with KB4343897 (build 16299.611). Here's a look:

• Provides protections against a new speculative execution side-channel vulnerability known as L1 Terminal Fault (L1TF) that affects Intel® Core® processors and Intel® Xeon® processors (CVE-2018-3620 and CVE-2018-3646). Make sure previous OS protections against Spectre Variant 2 and Meltdown vulnerabilities are enabled using the registry settings outlined in the Windows Client and Windows Server guidance KB articles. (These registry settings are enabled by default for Windows Client OS editions, but disabled by default for Windows Server OS editions.)
• Addresses an issue that causes high CPU usage that results in performance degradation on some systems with Family 15h and 16h AMD processors. This issue occurs after installing the June 2018 or July 2018 Windows updates from Microsoft and the AMD microcode updates that address Spectre Variant 2 (CVE-2017-5715 – Branch Target Injection).
• Updates support for the draft version of the Token Binding protocol v0.16.
• Addresses an issue that causes Device Guard to block some ieframe.dll class IDs after the May 2018 Cumulative Update is installed.
• Ensures that Internet Explorer and Microsoft Edge support the preload="none" tag.
• Addresses an issue that displays "AzureAD" as the default domain on the sign-in screen after installing the July 24, 2018 update on a Hybrid Azure AD-joined machine. As a result, users may fail to sign in in Hybrid Azure AD-joined scenarios when users provide only their username and password.
• Addresses an issue that adds additional spaces to content that's copied from Internet Explorer to other apps.
• Addresses a vulnerability related to the Export-Modulemember() function when used with a wildcard (*) and a dot-sourcing script. After installing this update, existing modules on devices that have Device Guard enabled will intentionally fail. The exception error is "This module uses the dot-source operator while exporting functions using wildcard characters, and this is disallowed when the system is under application verification enforcement". For more information, see https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-8200 and https://www.windowscentral.com/e?link=https%3A%2F%2Fclick.linksynergy.com%2Fdeeplink%3Fid%3DkXQk6%252AivFEQ%26mid%3D24542%26u1%3DUUwpUdUnU57966%26murl%3Dhttps%253A%252F%252Fwww.microsoft.com%252Fen-us%252F%253Fref%253Daka&token=RPOeV2k0
• Security updates to Windows Server.

A similar set of updates are also rolling out across older versions of Windows 10, including for PCs on the Creators Update and Anniversary Update. If you're ready to get your hands on these fixes, you can grab the latest updates now via Windows Update.