Windows Cdpsvc: Use-after-free leads to local privilege escalation

Summary

Microsoft Windows contains a use-after-free vulnerability (CWE-416) in the Connected Devices Platform Service (Cdpsvc). A local attacker with low privileges can exploit it to elevate privileges on the affected system. Exploitation is rated high complexity, requires an existing foothold on the system, and is not remotely exploitable.

Affected

• Windows 10 Version 1809 and Windows Server 2019 (incl. Server Core): 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 and 26H2: builds before 10.0.26200.9711 and 10.0.26300.9711
• Windows 11 Version 26H1: builds before 10.0.28000.3231
• Windows Server 2022: builds before 10.0.20348.5761
• Windows Server 2025 (incl. Server Core): builds before 10.0.26100.33650
• Note: the NVD CPE data lists only Windows 10 1809; the vendor's affected-product list is broader.

Fixed in

• Windows 10 1809 / Server 2019: 10.0.17763.9376 or later (verify the x64 entry in the MSRC table; the update is indexed as KB5126651, confirm on the Microsoft Update Catalog)
• Windows 10 21H2: 10.0.19044.7807 or later
• Windows 10 22H2: 10.0.19045.7807 or later
• Windows 11 24H2: 10.0.26100.9711 or later
• Windows Server 2022: 10.0.20348.5761 or later
• Windows Server 2025: 10.0.26100.33650 or later
• Other fixed builds: see the MSRC advisory. Fixes were released on 13 October 2026.

Workaround

Unknown. No vendor workaround has been identified; patching is the remediation.

Exploitation

• No public proof of concept or exploitation in the wild found as of 4 November 2026.
• CISA SSVC: Exploitation none, Automatable no, Technical Impact total.
• CVSS temporal vector includes E:U (exploit code maturity unproven).
• EPSS: 0.00275 at the time of the snapshot.

Our recommendation

• Install the October 2026 security update on all affected Windows 10, Windows 11 and Windows Server systems, prioritizing servers, shared endpoints and unpatched Windows 10 1809 systems.
• Check the installed build numbers against the fixed versions above.
• Limit local logon rights and keep endpoint protection and monitoring active, since exploitation requires an existing foothold.
• Monitor for unusual privilege changes on systems that have not yet been patched.

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-2026-83846 msrc.microsoft.com
• Microsoft Security Update Guide (en-US): CVE-2026-83846 msrc.microsoft.com
• Vulners MSCVE: CVE-2026-83846 (affected and fixed builds) vulners.com
• Vulners NVD: CVE-2026-83846 vulners.com
• OpenCVE: CVE-2026-83846 (SSVC data) app.opencve.io
• VulDB: CVE-2026-83846 vuldb.com

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 4 Nov 2026, 08:08.