Microsoft Windows 11: Use-after-free privilege escalation in telemetry component
Summary
A use-after-free flaw in the Windows Connected User Experiences and Telemetry component affects Windows 11 (versions 23H2, 24H2, 25H2, 26H1, 26H2) and Windows Server 2025. A locally authenticated user with low privileges can exploit it to gain elevated privileges, potentially up to SYSTEM. The attack requires local access and has high complexity, so it is not remotely exploitable. The main risk is a local user or a compromised account on a shared system.
Affected
- Windows 11 version 23H2: builds 10.0.22631.0 to below 10.0.22631.7652
- Windows 11 version 24H2: builds 10.0.26100.0 to below 10.0.26100.9711
- Windows 11 version 25H2: builds 10.0.26200.0 to below 10.0.26200.9711
- Windows 11 version 26H1: builds 10.0.28000.0 to below 10.0.28000.3231
- Windows 11 version 26H2: builds 10.0.26300.0 to below 10.0.26300.9711
- Windows Server 2025 (including Server Core): builds 10.0.26100.0 to below 10.0.26100.33650
Fixed in
- Windows 11 version 23H2: 10.0.22631.7652 or later
- Windows 11 version 24H2: 10.0.26100.9711 or later
- Windows 11 version 25H2: 10.0.26200.9711 or later
- Windows 11 version 26H1: 10.0.28000.3231 or later
- Windows 11 version 26H2: 10.0.26300.9711 or later
- Windows Server 2025: 10.0.26100.33650 or later
Verify the update number and build on the Microsoft Security Update Guide before deployment.
Workaround
Unknown.
Exploitation
- CISA SSVC assessment: exploitation none, automatable no, technical impact total.
- Not listed in the CISA KEV catalogue (as of the sources reviewed).
- No public proof of concept or in-the-wild exploitation found in the sources reviewed; this is not a confirmed absence.
Our recommendation
- Install the October 2026 Windows security update on all affected systems, prioritising multi-user servers, terminal servers and shared workstations.
- Check the build number of each system against the fixed versions above.
- Check whether Windows 11 23H2 is still within Microsoft's servicing period and plan an upgrade if it is not.
- Restrict local logon rights and review accounts with low privileges on critical systems.
Information from Microsoft (Patch Tuesday October 2026)
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Microsoft Security Update Guide: CVE-2026-83687 msrc.microsoft.com
- OpenCVE: CVE-2026-83687 (CISA SSVC, KEV status) app.opencve.io
- Strix: CVE-2026-83687 (CNA version ranges) www.strix.ai
- Vulners: NVD:CVE-2026-83687 vulners.com
- Vulners: MS:CVE-2026-83687 (Microsoft CNA entry) vulners.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, 08:34.
Original description (NVD)
Use after free in Windows Connected User Experiences and Telemetry allows an authorized attacker to elevate privileges locally.
NVD references (1)
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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