Microsoft’s emergency Windows Server patch fixes critical issues
▼ Summary
– Microsoft released emergency updates to fix installation failures and domain controller restart loops caused by April 2026 security patches.
– The out-of-band update for Windows Server 2025 resolves both known issues, while updates for other versions only address the restart problem.
– Some Windows Server 2025 devices may boot into BitLocker recovery after installing the problematic KB5082063 security update.
– Microsoft also fixed a separate bug causing unexpected upgrades to Windows Server 2025 on Server 2019 and 2022 systems.
– The company has issued multiple other emergency updates this year for issues like Bluetooth visibility and broken Microsoft account sign-ins.
Following the April 2026 security updates, Microsoft has issued out-of-band (OOB) emergency patches for critical problems impacting Windows Server environments. These unscheduled releases address two specific failures that emerged after the latest Patch Tuesday cycle. The first involves installation failures for the KB5082063 update on Windows Server 2025 systems. The second, more disruptive issue causes domain controllers to enter a restart loop due to crashes in the Local Security Authority Subsystem Service (LSASS). Microsoft notes this LSASS crash can also affect new domain controller setups or existing ones if they process authentication requests too early in the boot sequence.
To resolve these problems, Microsoft has provided targeted fixes. The company states that the OOB update for Windows Server 2025 (KB5091157) corrects both the installation failure and the domain controller restart loop. For other supported Windows Server versions, the released OOB updates address only the domain controller instability. In a related advisory, Microsoft also warned that some Windows Server 2025 devices might boot into BitLocker recovery mode and require a recovery key after installing the KB5082063 security update.
This recent flurry of emergency updates continues a pattern for Microsoft in 2026. The company recently fixed a long-standing bug, present since September 2024, that caused Windows Server 2019 and 2022 systems to upgrade to Windows Server 2025 unexpectedly. Earlier this year, other OOB releases resolved a Bluetooth device visibility issue and patched security flaws in the Routing and Remote Access Service (RRAS) management tool, which impacted hotpatch-enabled Windows 11 Enterprise devices. Additional emergency patches were also deployed to fix broken Microsoft account sign-ins and problems installing the March 2026 non-security preview update.
(Source: BleepingComputer)