Windows 11 KB5124008 update breaks domain trust for some usersnew
Microsoft is investigating Windows 11 KB5124008 breaking Active Directory domain trust, leaving some users unable to log in with valid credentials.
Administrators report the Windows 11 KB5124008 security update breaks the secure channel between domain-joined machines and Active Directory, causing login failures on Windows 11 25H2 systems after reboot. The failures are linked to the Machine Identity Isolation feature, which in enforcement mode moves machine account secrets into Credential Guard and removes the LSA copy; one admin saw 11 of roughly 256 devices affected. Workarounds include setting MachineIdentityIsolation to 0 and repairing the secure channel with Test-ComputerSecureChannel, though Microsoft has confirmed no root cause or official fix and warns disabling the feature can also break domain authentication.
Microsoft Excel KB5002914 update breaks copy and paste for some users
Microsoft's September Patch Tuesday update KB5002914 breaks copy-and-paste and formula dragging in Excel 2016 through 2024; uninstalling the update restores functionality.
Users on Reddit and Microsoft Q&A report that the KB5002914 security update shipped in the September 2026 Patch Tuesday breaks copy-and-paste, autofill, and formula dragging in Excel. The problem spans Office 2016 through 2024 across MSI and Click-to-Run installations, including Office LTSC Standard 2021, with some teams blocked after widespread patching. Uninstalling KB5002914 or downgrading the Office build restores functionality, though replacing the excel.exe binary is not recommended. BleepingComputer could not reproduce the issue on Excel 2019 Version 2508 Build 19127.20302 and contacted Microsoft for comment.
Remote Desktop Services Failures on Windows Servers Following September Update
September 2026 Patch Tuesday updates cause Windows Server 2019/2022/2025 RDS sessions to freeze, forcing administrators to roll back.
Cumulative updates KB5122876 (Windows Server 2019), KB5122882 (2022), and KB5122871 (2025) trigger Remote Desktop Services freezes hours after boot, with RDP connections hanging at 'Connecting…' and Event ID 20498 logged. Administrators trace the fault to an apparent deadlock in RDPSERVERBASE!WDLIB_Close during session teardown; only hard resets restore service and the issue recurs. The same September release patched roughly 973 vulnerabilities, including two actively exploited zero-days (CVE-2026-81963, CVE-2026-85880, both in CISA's KEV) and a critical RDS RCE, CVE-2026-69525 (CVSS 9.8). Workarounds include DISM-based removal of the update or an unofficial FeatureManagement registry key disabling the suspected audio-redirection code path; Microsoft has not yet confirmed the bug.