Windows StateRepository API: Use-after-free leads to local privilege escalation

Summary

A use-after-free flaw (CWE-416) in the Windows StateRepository API allows an authorized local user with low privileges to elevate their privileges. The flaw is rated CVSS 7.8 (High) and can affect confidentiality, integrity and availability on the local system. An attacker needs a valid local account or a prior foothold on the system, and the flaw cannot be exploited remotely. Microsoft released a fix in its October 2026 updates (published 13 October 2026).

Affected

• Windows 10 Version 1809 (builds before 10.0.17763.9376)
• Windows 10 Version 21H2 (builds before 10.0.19044.7807)
• Windows 10 Version 22H2 (builds before 10.0.19045.7807)
• Windows 11 Version 23H2 (builds before 10.0.22631.7652)
• Windows 11 Version 24H2 (builds before 10.0.26100.9711)
• Windows 11 Version 25H2 (builds before 10.0.26200.9711)
• Windows 11 Version 26H1 (builds before 10.0.28000.3231)
• Windows 11 Version 26H2 (builds before 10.0.26300.9711)
• Windows Server 2019, including Server Core (builds before 10.0.17763.9376)
• Windows Server 2022 (builds before 10.0.20348.5761)
• Windows Server 2025, including Server Core (builds before 10.0.26100.33650)
• Note: The CPE entry lists only Windows 10 1809. The other versions above are also affected according to the CVE record.

Fixed in

• Windows 10 Version 1809 and Windows Server 2019: 10.0.17763.9376 or later
• Windows 10 Version 21H2: 10.0.19044.7807 or later
• Windows 10 Version 22H2: 10.0.19045.7807 or later (verify on MSRC, third-party data shows a conflicting range)
• Windows 11 Version 23H2: 10.0.22631.7652 or later
• Windows 11 Version 24H2: 10.0.26100.9711 or later
• Windows 11 Version 25H2 and 26H2: 10.0.26200.9711 or later and 10.0.26300.9711 or later
• Windows 11 Version 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
• Restart the system after installing the update.

Workaround

No workaround documented. Installing the security update is the fix.

Exploitation

• No evidence of active exploitation found. Microsoft's exploitability rating could not be verified.
• No public proof of concept found.
• EPSS is very low (about 0.0035), which indicates a low predicted probability of exploitation.
• CISA KEV status not verified.

Our recommendation

• Install the October 2026 Windows security update on all affected systems, prioritising multi-user systems, terminal servers and Remote Desktop hosts.
• Verify the correct update (KB) and build numbers on the MSRC page before rollout.
• Replace Windows 10 Version 1809 and other unsupported Windows versions, as they no longer receive standard security updates.
• Patch CVE-2026-85910 (information disclosure in the same component) in the same cycle.
• Restrict local logon to necessary accounts and monitor for unusual privilege changes.

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-2026-85911 msrc.microsoft.com
• Vulners: NVD data for CVE-2026-85911 vulners.com
• Vulners: VulnCheck data for CVE-2026-85911 vulners.com
• OpenCVE: CVE-2026-85911 app.opencve.io
• Strix: CVE-2026-85911 www.strix.ai

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, 01:44.