Picture this: You're an IT admin counting on seamless, restart-free updates to keep your Windows Server 2025 humming smoothly – only for a critical security patch to throw a wrench in the works and force those dreaded reboots. Frustrating, right? But stick around, because this story from the world of Microsoft updates reveals a tale of unintended consequences, quick fixes, and lessons in patching priorities.
Microsoft's WSUS Security Patch Accidentally Disrupts Hotpatching on Windows Server 2025
Key Insights:
- A vital WSUS security update unexpectedly interfered with hotpatching features on certain Windows Server 2025 systems.
- The problem specifically impacts servers that are part of Microsoft’s Hotpatch initiative.
- Microsoft has now provided an updated solution that addresses the security flaw without compromising hotpatch capabilities.
Recently, a Microsoft security update designed to tackle a serious WSUS vulnerability inadvertently caused issues with hotpatching on Windows Server 2025 installations. This meant that restart-free patching was disabled for some servers, leaving administrators dependent on conventional cumulative updates until January 2026.
For those new to this, let's break it down simply: WSUS, or Windows Server Update Services (more details at https://petri.com/windows-server-update-services-wsus-2012-installation/), is Microsoft's tool for managing updates across networks. The vulnerability in question, known as CVE-2025-59287 (see https://nvd.nist.gov/vuln/detail/CVE-2025-59287), involved a weakness in how WSUS processed certain requests. This flaw could allow attackers to bypass safeguards and run harmful code remotely on a server, creating significant risks for businesses and organizations.
And this is the part most people miss – how a fix for one critical issue can unexpectedly ripple into another, highlighting the delicate balance in software updates.
How Did the Update Impact Windows Server 2025 Hotpatching?
Just last month, Microsoft issued an out-of-band (OOB) security update, labeled KB5070881 (available at https://support.microsoft.com/en-us/topic/october-23-2025-kb5070881-os-build-26100-6905-out-of-band-8e7ac742-6785-4677-87e4-b73dd8ac0122), to patch this actively exploited WSUS flaw. However, this update accidentally turned off hotpatching (learn more about enabling it at https://petri.com/enable-windows-server-hotpatching/) on select Windows Server 2025 machines that were enrolled in the Hotpatch program.
As Microsoft explained, “A very limited number of Hotpatch-enrolled machines received the update before the issue was corrected. The update is now offered only to machines that are not enrolled to receive Hotpatch updates.” They emphasized that “This issue only impacts Windows Server 2025 devices and virtual machines (VMs) enrolled to receive Hotpatch updates.”
To clarify for beginners: Hotpatching is a fantastic feature that allows certain updates to apply without needing a server restart, minimizing downtime – think of it as a quick tune-up instead of a full engine overhaul. But the KB5070881 update caused enrolled systems to lose their hotpatch status, meaning no hotpatch updates in November and December. Admins had to fall back on standard updates, which do require restarts. This inconvenience lingered until the January 2026 baseline update, set to restore hotpatching and bring back those restart-free patches.
But here's where it gets controversial: Was this a forgivable oversight in the rush to fix a security threat, or a sign that Microsoft's update process needs more rigorous testing to avoid such disruptions? After all, in high-stakes environments like data centers, even temporary downtime can mean lost productivity and costs – a trade-off that sparks debate among IT pros.
Microsoft's Follow-Up and the New Resolution
The good news is, Microsoft swiftly rolled out a revised update, KB5070893 (found at https://support.microsoft.com/en-us/topic/october-24-2025-kb5070893-os-build-26100-6905-security-update-for-windows-server-update-services-78f3720c-9511-4deb-b0d7-7bed2016fefd), which fixes the vulnerability without sabotaging hotpatching. If you've downloaded KB5070881 but haven't installed it yet, head to Settings > Windows Update, unpause, and rescan to get KB5070893 instead. According to Microsoft, servers that apply this new patch will keep receiving hotpatch updates through November and December.
Additionally, Microsoft adjusted WSUS error reporting (check out https://learn.microsoft.com/en-us/windows/release-health/status-windows-11-25h2#task-manager-process-might-continue-to-run-in-background-after-app-is-closed) to conceal synchronization error specifics. There were also unrelated improvements, such as fixing problems in Windows 11's Task Manager, the Media Creation Tool, and update glitches on Windows 11 version 24H2 – little perks that show Microsoft's broader commitment to refining the user experience.
As we wrap this up, let's ponder: In an era where cybersecurity threats loom large, should companies like Microsoft prioritize speed in releasing patches over thorough testing, potentially at the expense of user convenience? Or is the rapid response to exploits a necessary evil? Do you think this incident reflects poorly on Microsoft's quality control, or is it just another bump in the road of tech innovation? Share your thoughts in the comments – I'd love to hear if you've experienced similar update woes or if you see this as a call for better safeguards in software deployment!
