facing Netlogon, port exahaustion, ping drop , rdp issue on VMs hosted on Hyper-V and Vmware after september month patch installation even RDS feature is not installed

Hello @Dhananjay Srivastava

Microsoft has confirmed an issue with the September 2026 Windows security updates that can cause Remote Desktop instability, and it is not limited to servers with the full Remote Desktop Services (RDS) role installed.

Microsoft reports that after the September 2026 security updates, some Windows devices with Remote Desktop enabled can experience RDP connections failing after several minutes, sign-in failures, or the system hanging at “Please wait for the Remote Desktop Configuration.” Related components such as MMC and File Explorer can also become unresponsive.

Microsoft has released out-of-band (OOB) updates that resolve this known RDP/RDS issue. For example, Windows Server 2022 systems affected after KB5122882 should install the September 14 OOB update KB5129237, or a later cumulative update containing the fix. Microsoft released similar OOB fixes for the other affected Windows versions.

However, don't assume Netlogon problems, ephemeral-port exhaustion, and ping loss are all caused by the same known issue. Microsoft's published description currently confirms the RDP/RDS instability but doesn't document port exhaustion or ICMP/ping loss as symptoms of that regression.

Since you're seeing this on VMs running on both Hyper-V and VMware, the guest Windows update/build is also more important to compare than the underlying hypervisor.

Could you provide the following from one affected VM?

winver
Get-HotFix | Sort-Object InstalledOn -Descending | Select-Object -First 10

and:

netstat -ano
netsh int ipv4 show dynamicport tcp

Also, let us know the exact Windows Server/Windows client version, September KB installed, whether the problem disappears after reboot, and what you mean by “port exhaustion” (for example, large numbers of TIME_WAIT connections, Event ID 4227/4231, or an application-specific error).

If the affected machines have one of the September updates associated with Microsoft's RDP issue, install the appropriate OOB/latest cumulative update first, then retest. If RDP is fixed but Netlogon, ping loss, or port exhaustion remain, investigate those symptoms separately rather than treating them as one regression.

References:

Windows Server 2025 known issues and notifications

Windows Server 2016 resolved issues

Windows 11 24H2 resolved issues

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