Applies ToWindows Server 2012 R2 ESU

Release Date:

12/03/2024

Version:

Monthly Rollup

IMPORTANT If you plan to install this update on a domain controller (DC), we highly recommend that you install update KB5037426 instead (March 22, 2024). This out-of-band update addresses a known issue that affects the Local Security Authority Subsystem Service (LSASS). It might leak memory on DCs.

Important The installation of this Extended Security Update (ESU) might fail when you try to install it on an Azure Arc-enabled device that is running Windows Server 2012 R2. For a successful installation, please make sure all Subset of endpoints for ESU only are met as described in Connected Machine agent network requirements.

Reminder

  • Windows 8.1 reached end of support (EOS) on January 10, 2023, at which point technical assistance and software updates are no longer provided. If you have devices running Windows 8.1, we recommend upgrading them to a more current, in-service, and supported Windows release. If devices do not meet the technical requirements to run a more current release of Windows, we recommend that you replace the device with one that supports Windows 11.

    Microsoft will not be offering an Extended Security Update (ESU) program for Windows 8.1. Continuing to use Windows 8.1 after January 10, 2023 may increase an organization’s exposure to security risks or impact its ability to meet compliance obligations. For more information, see Windows 8.1 support will end on January 10, 2023.

    We recommend upgrading to a later version of Windows. For more information, see Upgrade to a later version of Windows.

  • Windows Server 2012 R2 reached end of support (EOS) on October 10, 2023. Extended Security Updates (ESUs) are available for purchase and will continue for three years, renewable on an annual basis, until the final date on October 13, 2026. For more information, see Windows Server End of Support: Key Dates. For information about the procedure to continue receiving security updates, see KB5031043. We recommend upgrading to a later version of Windows Server. For more information, seeLearn about upgrading Windows Server.

  • Windows Embedded 8.1 Industry Enterprise and Windows Embedded 8.1 Industry Pro reached end of support (EOS) on July 11, 2023. Therefore, technical assistance and software updates are no longer provided.

Summary

Learn more about this cumulative security update, including improvements, any known issues, and how to get the update.

Note For information about the various types of Windows updates, such as critical, security, driver, service packs, and so on, see Description of the standard terminology that is used to describe Microsoft software updates. To view other notes and messages, see the Windows 8.1 and Windows Server 2012 R2 update history home page.

Improvements

This cumulative security update includes improvements that are part of update KB5034819 (released February 13, 2024). This update also makes improvements for the following issue:

  • The Local Security Authority (LSA) might fail while interfacing with third-party software.

For more information about the resolved security vulnerabilities, please refer to the Deployments | Security Update Guide and the March 2024 Security Updates.

Known issues in this update

Symptoms

Next step

Following installation of the March 2024 security update, released March 12, 2024 (KB5035885), Local Security Authority Subsystem Service (LSASS) may experience a memory leak on domain controllers (DCs). This is observed when on-premises and cloud-based Active Directory Domain Controllers service Kerberos authentication requests.

Excessive memory leaks may cause LSASS to crash, which triggers an unscheduled reboot of underlying domain controllers (DCs).

Note This issue does not occur on Home devices. It affects only environments in organizations using some Windows Server platforms.

This issue is resolved in update KB5037426.

How to get this update

Before installing this update

We strongly recommend that you install the latest servicing stack update (SSU) for your operating system before you install the latest Monthly Rollup. SSUs improve the reliability of the update process to mitigate potential issues while installing the Monthly Rollup and applying Microsoft security fixes. For general information about SSUs, see Servicing stack updates and Servicing Stack Updates (SSU): Frequently Asked Questions.

If you use Windows Update, the latest SSU (KB5035968) will be offered to you automatically. To get the standalone package for the latest SSU, search for it in the Microsoft Update Catalog.

Language packs

If you install a language pack after you install this update, you must reinstall this update. Therefore, we recommend that you install any language packs that you need before you install this update. For more information, see Learn about adding a language pack to Windows.

Install this update

Release Channel

Available

Next Step

Windows Update and Microsoft Update

Yes

None. This update will be downloaded and installed automatically from Windows Update.

Microsoft Update Catalog

Yes

To get the standalone package for this update, go to the Microsoft Update Catalog website.

To download updates from the Update Catalog, see Steps to download updates from the Windows Update Catalog.

Windows Server Update Services (WSUS)

Yes

This update will automatically sync with WSUS if you configure Products and Classifications as follows:

Product: Windows Server 2012 R2

Classification: Security Updates

For more information, see Configure classifications and products to synchronize.

File information

For a list of the files that are provided in this update, download the file information for update KB5035885.

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