Windows Device Association Service: Use-after-free leads to privilege escalation

Summary

The Windows Device Association Service in multiple Windows 10, Windows 11 and Windows Server releases contains a use-after-free flaw (CWE-416). A local attacker with low privileges and an authorized account can exploit it to gain elevated rights, potentially up to SYSTEM. No user interaction is required, and the flaw is not reachable from the internet by itself. Microsoft has not marked it as publicly disclosed, and no exploitation has been reported.

Affected

• Windows 10 Version 1809 and Windows Server 2019 (including Server Core): 10.0.17763.0 before 10.0.17763.9376
• Windows 10 Version 21H2: 10.0.19044.0 before 10.0.19044.7807
• Windows 10 Version 22H2: 10.0.19045.0 before 10.0.19045.7807
• Windows 11 Version 23H2: 10.0.22631.0 before 10.0.22631.7652
• Windows 11 Version 24H2: 10.0.26100.0 before 10.0.26100.9711
• Windows 11 Version 25H2: 10.0.26200.0 before 10.0.26200.9711
• Windows 11 Version 26H1: 10.0.28000.0 before 10.0.28000.3231
• Windows 11 Version 26H2: 10.0.26300.0 before 10.0.26300.9711
• Windows Server 2022: 10.0.20348.0 before 10.0.20348.5761
• Windows Server 2025 (including Server Core): 10.0.26100.0 before 10.0.26100.33650

Fixed in

• Windows 10 1809 / Server 2019: build 10.0.17763.9376 or later (update package reported as KB5126651, not independently verified)
• Windows 10 21H2: 10.0.19044.7807 or later
• Windows 10 22H2: 10.0.19045.7807 or later
• Windows 11 23H2: 10.0.22631.7652 or later
• Windows 11 24H2: 10.0.26100.9711 or later
• Windows 11 25H2 and 26H2: 10.0.26200.9711 and 10.0.26300.9711 or later
• Windows 11 26H1: 10.0.28000.3231 or later
• Windows Server 2022: 10.0.20348.5761 or later
• Windows Server 2025: 10.0.26100.33650 or later

Workaround

• A vendor patch is available; installing it is the recommended fix.
• Unverified interim measure from a third-party aggregator: disable or restrict the Device Association Service until patching is possible. Microsoft has not confirmed this. Check first whether disabling the service breaks device pairing on your clients.

Exploitation

• Microsoft lists the vulnerability as not publicly disclosed.
• CISA SSVC assessment: exploitation none, automatable no, technical impact total.
• No exploitation in the wild found in the sources reviewed; no public proof of concept found; no CISA KEV entry found.
• Microsoft's own exploitation field could not be confirmed from the sources reviewed.

Our recommendation

• Install the October 2026 cumulative update on all affected Windows 10, Windows 11 and Windows Server systems, prioritising multi-user systems, terminal servers, kiosks and 1809 / Server 2019 hosts.
• Plan the upgrade of Windows 10 1809 systems that cannot be patched.
• Restrict local logons on shared machines and review accounts with local access.
• Confirm the current NVD status of the CVE, as the sources show differing dates.
• Priority: medium.

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 Response Center: CVE-2026-85332 msrc.microsoft.com
• Microsoft Security Update Guide (en-US): CVE-2026-85332 msrc.microsoft.com
• Vulners NVD mirror: CVE-2026-85332 vulners.com
• Vulners Microsoft advisory mirror: MS:CVE-2026-85332 vulners.com
• OpenCVE: CVE-2026-85332 app.opencve.io

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, 02:26.