Microsoft Remote Desktop Client: Use-after-free leads to remote code execution

Summary

A use-after-free vulnerability (CWE-416) in the Windows Remote Desktop Client allows remote code execution over the network. The CVSS vector requires user interaction and high attack complexity, so an attacker must lure a user into connecting to a malicious RDP endpoint or otherwise triggering the flaw. Windows 10 Version 1607 and Windows Server 2016 are affected and cannot receive the fix on devices without extended security updates, because 1607 LTSB reached end of support on 13 October 2026.

Affected

• Windows 10 Version 1607: builds below 10.0.14393.9612
• Windows Server 2016: builds below 10.0.14393.9612
• Windows 10 Version 1809: builds below 10.0.17763.9376
• Windows 10 Version 21H2: builds below 10.0.19044.7807
• Windows 10 Version 22H2: builds below 10.0.19045.7807
• Windows 11 Version 23H2: builds below 10.0.22631.7652
• Windows 11 Version 24H2: builds below 10.0.26100.9711
• Windows 11 Version 25H2: builds below 10.0.26200.9711
• Windows 11 Version 26H1: builds below 10.0.28000.3231
• Windows 11 Version 26H2: builds below 10.0.26300.9711
• Windows Server 2012 and 2012 (Server Core): builds below 6.2.9200.26434
• Windows Server 2012 R2 and 2012 R2 (Server Core): builds below 6.3.9600.23470

Fixed in

• Install the October 2026 Windows security update or a later cumulative update for each affected version.
• Windows 10 Version 1607 and Windows Server 2016: build 10.0.14393.9612 or later; install the latest cumulative update.
• Note: the 22H2 range in some secondary data sources is internally inconsistent; Microsoft's advisory is authoritative.

Workaround

• No vendor-specific workaround identified.
• Restrict RDP access to trusted hosts through firewall rules or VPN (generic measure, not a vendor fix).

Exploitation

• No evidence of exploitation in the wild found.
• CISA SSVC in the CVE record: exploitation none, automatable no.
• No public proof of concept found.

Our recommendation

• Prioritise Windows 10 Version 1607 and Windows Server 2016 devices: they are out of support or nearing end of support (Server 2016 extended support ends 12 January 2027). Migrate them or evaluate Extended Security Updates; confirm with Microsoft whether the October build is delivered to non-ESU devices.
• Patch all other affected Windows systems with the October 2026 update.
• Patch the Remote Desktop Client batch together, including CVE-2026-69995 from the same release.
• Restrict RDP access to trusted hosts only and avoid connecting to unknown RDP endpoints.
• Monitor for unusual RDP sessions and crashes on endpoints such as kiosks, POS terminals and thin clients.

Public exploits iAttack code is publicly available (PoC on GitHub, Metasploit or Exploit-DB).

PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.

Research sources

• Microsoft Security Update Guide: CVE-2026-69996 msrc.microsoft.com
• Microsoft release health: Windows 10 1607 and Windows Server 2016 learn.microsoft.com
• Vulners: CVE-2026-69996 vulners.com
• OpenCVE: CVE-2026-69996 app.opencve.io
• VulDB: CVE-2026-69996 vuldb.com
• SonicWall: Microsoft security bulletin coverage for October 2026 www.sonicwall.com
• Wikipedia: Windows Server 2016 en.wikipedia.org

Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 2 Nov 2026, 19:16.