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Microsoft confirms that its latest Windows 11 security update is experiencing issues with installation due to insufficient free space on the EFI System Partition (ESP), leading to automatic rollback on affected devices. Users can mitigate this issue by using the Known Issue Rollback or configuring Group Policy in enterprise environments.
Windows 11 security update KB5089549 is experiencing issues with installation due to insufficient free space on the EFI System Partition (ESP). The problem causes automatic rollback on affected devices and fails at approximately 35-36% completion. Affected users have reported error messages stating "Something didn't go as planned. Undoing changes." Microsoft advises users to mitigate the issue by using the Known Issue Rollback or configuring Group Policy in enterprise environments. The company has released other updates recently, highlighting ongoing efforts to improve stability and security.
Microsoft, the tech giant, has recently confirmed that its latest security update for Windows 11, KB5089549, is experiencing issues with installation on some systems. The problem, which was identified by Sergiu Gatlan in his recent article, is caused by insufficient free space on the EFI System Partition (ESP), leading to the update automatically rolling back on affected devices.
In a statement, Microsoft acknowledged that this issue affects devices with limited free space on the ESP, particularly those with 10 MB or less of available space. The installation process may proceed through the initial phases but fail during the reboot phase at approximately 35-36% completion. Affected users have reported encountering an error message stating "Something didn't go as planned. Undoing changes." and log entries pointing to insufficient ESP free space, such as "SpaceCheck: Insufficient free space," "ServicingBootFiles failed. Error = 0x70," and "SpaceCheck: used by third-party/OEM files outside of Microsoft boot directories."
Microsoft has advised affected customers to mitigate this issue by using the Known Issue Rollback (a Windows feature that reverses buggy updates pushed via Windows Update). In enterprise-managed environments where IT departments control Windows updates, admins can manually mitigate it by installing and configuring the Group Policy. This requires installing and configuring the Group Policy for your version of Windows to resolve the issue and restarting the device(s) to apply the group policy setting.
The known issue is not an isolated incident, as Microsoft has released numerous other bug fixes, security patches, and improvements in recent months. In April 2026, a cumulative update (KB5083769) caused backup software failures on some systems, while in March 2026, Windows updates broke sign-ins for Teams and OneDrive.
It's worth noting that this issue highlights the importance of ensuring sufficient free space on the ESP, particularly in situations where devices have limited storage capacity. Users are advised to monitor their system's disk space and take necessary precautions to avoid similar issues in the future.
In conclusion, Microsoft has acknowledged a known issue with its Windows 11 security update KB5089549 and is providing guidance on how to mitigate it. The company has also released several other updates recently, highlighting the ongoing efforts to improve the stability and security of its operating systems.
Microsoft confirms that its latest Windows 11 security update is experiencing issues with installation due to insufficient free space on the EFI System Partition (ESP), leading to automatic rollback on affected devices. Users can mitigate this issue by using the Known Issue Rollback or configuring Group Policy in enterprise environments.
Related Information:
https://www.ethicalhackingnews.com/articles/Microsofts-Windows-11-Security-Update-Install-Issues-A-Deep-Dive-into-the-Known-Issue-ehn.shtml
https://www.bleepingcomputer.com/news/microsoft/microsoft-confirms-kb5089549-windows-11-security-update-install-issues/
Published: Mon May 18 04:13:07 2026 by llama3.2 3B Q4_K_M
