Windows Server · 2025 · Release · Out-of-band update
October 20, 2025—KB5070773 (OS Build 26100.6901) Out-of-band
- Release
- Cumulative update
- KB5070773 — Microsoft's article, opens in a new tab
Windows Server 2025: Current LTSC release
Microsoft's known issues — KB5070773
- Issue Known issue Active Directory domain controllers (DC) running on Windows Server 2025 and also running the schema master Flexible Single Master Operation (FSMO) role , will allow duplicate entries in attributes of schema objects. Commonly affected attributes include auxiliaryClass , possSuperiors , mayContain with values such as msExchBaseClass , msExchContainer , and msExchVirtualDirectoryFlags . When this occurs, Active Directory replication fails with a schema mismatch error, such as error 8418: The replication operation failed because of a schema mismatch between the servers involved." This issue can be observed when running Exchange Server setup forestprep and the schema master role for Active Direct Workaround: This issue is addressed KB5068861 . This issue is addressed in KB5068861 . Windows Server 2025 users aren’t affected, and no action is required. To learn how this issue affects Windows 11, see the following: Windows 11, version 25H2 Windows 11, version 24H2
Known issues — reported on the forum
- Issue Fix Windows Server 2025 WinRE USB Input Bug After KB5066835—Patch to KB5070773
- Issue WinRE Startup Fix: March 2026 KB5075039 Resolves October 2025 Regression
- Issue Windows October 2025 Update Regression Breaks WinRE and Localhost
- Issue Windows 11 Shutdown Bug with Secure Launch KB5073455 and OOB KB5077797
In the news
- Issue Fix Windows Server 2025 WinRE USB Input Bug After KB5066835—Patch to KB5070773
- Fix Windows 11 January 2026 Patch Tuesday: Regressions and Emergency Fixes
- Coverage Windows 11 24H2 OOBE and Recovery Upgrades: Quick Machine Recovery
- Issue WinRE Startup Fix: March 2026 KB5075039 Resolves October 2025 Regression
- Coverage Windows 11 Internet Lost After Update: Causes, Mitigation and Best Practices
- Issue Windows October 2025 Update Regression Breaks WinRE and Localhost
- Fix WinRE Failures After October 2025 Patch: Windows 11 Quick Fix and Windows 10 March 2026 Patch
- Fix Windows 11 Connectivity Failures After Updates: Fixes for Connected but No Internet