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Windows 11 preview KB5127936 fixes Remote Desktop and VPN failures

3 sources · 4 articlesFirst reported Updated ()2
What's new

October 30: GBHackers ties the failure to KB5124010 build 26200.9550, says Microsoft marked the issue resolved on October 28, and notes there is no CVE and the fix is not an out-of-band security patch.

Merged summary · x-ai/grok-4.7 · rewritten as coverage arrivesSummaries by Vani AI

October 28 preview KB5127936 restores non-admin Remote Desktop and Always On VPN connections broken by September Windows 11 updates.

Microsoft’s October 28 preview update KB5127936 fixes Windows 11 Remote Desktop and Always On VPN failures that followed September 2026 updates. Non-admin Remote Desktop connections fail with error 0xC000000D when Administrator protection is enabled, after the September 22 non-security preview KB5124010 or later updates. Enterprise-managed hosts are mainly affected; Windows Server is not listed. The same preview stops Always On VPN sessions stuck on Connecting or reporting a port already in use when automatic selection used IKEv2 and SSTP. Microsoft had incorrectly marked that VPN issue fixed in October cumulative updates. Temporary policy and single-protocol workarounds remain until the next Patch Tuesday.

Key facts
  • Affected clients: Windows 11 24H2, 25H2, 26H1, and 26H2; Windows Server is not listed.
  • KB5124010 is the September 22 preview tied to build 26200.9550 on 25H2.
  • KB5127936 raises 25H2 and 26H2 to builds 26200.9818 and 26300.9818.
  • Security baselines for 24H2, 25H2, and 26H2 enable Administrator protection by default.
  • No CVE or exploitation is described; the fix is a preview, not an out-of-band security patch.
  • Until patched, admins can reset User Account Control Type Of Admin Approval Mode.
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Timeline

dated events in the reporting · oldest first
  1. Sep 22, 2026Non-security preview KB5124010 begins Remote Desktop failures · Cyber Security News
  2. Oct 13, 2026Microsoft opens an investigation into the Remote Desktop failures · BleepingComputer
  3. Oct 28, 2026Preview KB5127936 released and the issue marked resolved · GBHackers

What each outlet adds

beyond the shared facts
  • Cyber Security NewsLists four Windows 11 versions and the fixed 25H2 and 26H2 builds.
  • BleepingComputerReports the Always On VPN failures and Microsoft’s earlier incorrect fix claim.
  • GBHackersGives KB5124010 build 26200.9550 and says no CVE or out-of-band patch.
Vendors
Microsoft
Products
Windows 11Remote DesktopAlways On VPNKB5127936

Coverage

oldest first · one row per article · UTC
  1. · 1d ago BleepingComputerFirst report

    Microsoft fixes Remote Desktop failures after recent Windows updates

    KB5127936, released October 28, restores non-admin connections that failed with error 0xC000000D when Administrator protection is enabled.

  2. · 13h ago Cyber Security News

    Microsoft fixes Windows 11 Remote Desktop failures after recent updates

    Non-admin sessions failed with error 0xC000000D on hosts using Administrator protection after the September 22 preview.

  3. · 10h ago BleepingComputer

    Microsoft fixes Always On VPN failures from September Windows 11 updates

    KB5127936 stops connections stuck on Connecting or reporting a port already in use; a single-protocol workaround remains.

  4. · 10h ago GBHackers

    Microsoft fixes Windows 11 Remote Desktop failures for non-admins

    KB5127936, out October 28, clears error 0xC000000D on hosts with Administrator protection; Windows Server is not affected.