Office 2021 and Windows Server 2012 get final patches on October 13

Microsoft's October 13 Patch Tuesday is the last security release for a long list of products that many companies still run. Office 2021 and Office LTSC 2021 reach end of support that day. So does the third and final year of paid Extended Security Updates for Windows Server 2012 and 2012 R2, and Windows 11 version 24H2 in its Home and Pro editions.

For IT teams, anything on that list still in use after Tuesday is unpatched from November on. There is no fourth year of ESUs for Windows Server 2012 and no ESU program at all for Office 2021. Audit findings and cyber insurance questionnaires tend to ask about exactly these products.

What stops on October 13

Microsoft's 2026 lifecycle calendar lists these cutoffs for October 13:

Windows Server 2012 left extended support on October 10, 2023. Microsoft then sold ESUs one year at a time for on-premises servers and gave them free to servers moved into Azure. Both run out this week. Microsoft's announcement for Office LTSC 2021 points customers to Microsoft 365 Apps, or to Office LTSC 2024 for those who want to stay on-premises.

Windows 11 24H2 only ends for Home and Pro. Enterprise and Education editions of 24H2 are supported until October 2027, BleepingComputer reported, and Home and Pro machines that IT does not manage will be moved to 25H2 automatically. A Pro laptop that IT does manage, with feature updates held back by policy, will stop getting fixes.

Exchange 2016 and 2019 follow at month end

Exchange Server 2016 and 2019 are on a second, six-month ESU period that Microsoft announced in April. Microsoft's Exchange team said in July that it would not extend the program again. Messageware, an Exchange tools vendor, puts the period at May 1 to October 31, 2026, with updates sent privately to enrolled customers and only for Critical and Important flaws. Todd Schell of Ivanti, writing in Help Net Security's Patch Tuesday forecast, expects Tuesday's release to mark the end of Exchange ESU support.

The way out is Exchange Server Subscription Edition (SE) or Exchange Online. Exchange 2019 servers on CU14 or CU15 can upgrade in place to SE. Exchange 2016 cannot: it needs new SE servers and a mailbox move.

Tuesday's release is likely to be large. Schell counted 973 CVEs across Microsoft's portfolio in September, a record, and expects a high count again. Microsoft also plans to fix an Excel copy-and-paste failure and a File History and Windows Backup problem that the September updates caused.

Next on the calendar is November 10, when .NET 8, PowerShell 7.4 and Windows 11 Enterprise and Education 23H2 reach end of servicing.