October 10, 2023—KB5031407 (Security-only update)

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.Upgrade to Windows 10: FAQUpgrade to Windows 11: FAQ
• 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.Learn 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 security-only 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, please see the following article. To view other notes and messages, see the Windows 8.1 and Windows Server 2012 R2 update history home page.

Improvements

This update makes improvements for the following issues:

• Addresses an issue in which an external bind might fail after Windows updates released on or after May 2023 are installed. This leads to issues with Lightweight Directory Access Protocol (LDAP) queries and authentication.
• This update includes daylight saving time (DST) changes for Ukraine and Greenland. For more information, see the Daylight Saving Time & Time Zone Blog.
  For more information about the resolved security vulnerabilities, please refer to the Deployments | Security Update Guide and the October 2023 Security Updates.

Known issues in this update

We are currently not aware of any issues with this update.

How to get this update

Before installing this updateWe strongly recommend that you install the latest servicing stack update (SSU) for your operating system before you install the latest security-only update. SSUs improve the reliability of the update process to mitigate potential issues while installing the security-only update 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 (KB5030329) will be offered to you automatically. To get the standalone package for the latest SSU, search for it in the Microsoft Update Catalog.

REMINDER If you are using Security-only updates, you will also need to install all previous Security-only updates and the latest cumulative update for Internet Explorer (KB5031355).

Language packsIf 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.Learn about adding a language pack to WindowsInstall this update****Release Channel	Available	Next Step
Windows Update and Microsoft Update	No	See the other options below.
Microsoft Update Catalog	Yes	To get the standalone package for this update, go to the Microsoft Update Catalog website.
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 R2Classification: Security Update

File information

For a list of the files that are provided in this update, download the file information for update KB5031407.

References

Learn about the standard terminology that is used to describe Microsoft software updates.