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.
- KB5122876, KB5122882, and KB5122871 cause session hosts to freeze hours after boot; only hard resets recover.
- Suspected deadlock in RDPSERVERBASE!WDLIB_Close; Event ID 20498 and Winlogon 6005 mark affected hosts.
- DISM uninstall restores stability, while WUSA fails because the Servicing Stack Update is bundled.
- Unofficial workaround disables the faulting audio-redirection path via a FeatureManagement registry key.
- September updates also fixed ~973 vulnerabilities, including KEV-listed zero-days CVE-2026-81963 and CVE-2026-85880.
- Vendors
- Microsoft
- Organizations
- CISACyber Security NewsReddit
Vulnerabilities mentioned
All| CVE | Vulnerability | CVSS | EPSS | Signals | Published |
|---|---|---|---|---|---|
CVE-2026-69525+1 related CVE | Use-After-Free RCE in Windows Remote Desktop Services | 9.8 group max | 1% | ||
CVE-2026-81963+1 related CVE | Local Privilege Escalation via Link Following in Windows Update Stack | 7.8 | <1% | KEV | KEV |
From the original article
3 min read at cybersecuritynews.com
Windows administrators worldwide are grappling with a disruptive Remote Desktop Services (RDS) bug that surfaced immediately after Microsoft shipped its September 2026 Patch Tuesday cumulative updates. Session hosts running Windows Server 2019, 2022, and 2025 have begun freezing hours after boot, leaving RDP connections stuck at “Connecting…” and preventing logged-in users from disconnecting or logging […]
By Guru Baran · cybersecuritynews.com
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