Windows Clipboard Server: Local privilege escalation via null pointer dereference
Summary
A null pointer dereference in the Windows Clipboard Server component allows an authorized local attacker to elevate privileges. The attacker needs local access and an existing low-privilege account, and exploitation is complex (CVSS 3.1 base score 7.0, High). The risk is highest after another compromise, such as phishing or stolen credentials, on multi-user, terminal or RDS hosts.
Affected
- 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 2019, including Server Core (builds below 10.0.17763.9376)
- Windows Server 2022 (builds below 10.0.20348.5761)
- Windows Server 2025, including Server Core (builds below 10.0.26100.33650)
Fixed in
- Windows 10 Version 1809 / Windows Server 2019: build 10.0.17763.9376 or later (October 2026 cumulative update, reported as KB5126651 by Tenable; to be confirmed on MSRC)
- Other listed products: the October 2026 security update for each respective build (builds as listed above, to be verified on MSRC)
Workaround
Unknown. No vendor workaround is known because a patch is available. Apply the October 2026 security update.
Exploitation
- No evidence of in-the-wild exploitation found; not found in CISA KEV in our searches (check the catalogue directly)
- CISA SSVC: exploitation none, not automatable, total technical impact
- Microsoft exploit code maturity: Unproven (E:U)
- No public proof-of-concept found (search not exhaustive)
- EPSS very low at 0.0027
Our recommendation
- Identify all affected systems early, especially Windows 10 1809 and Windows Server 2019 (same build 17763).
- Install the October 2026 security update on all affected builds, prioritising terminal servers, RDS hosts and shared multi-user systems.
- Verify KB numbers and build numbers on the MSRC Security Update Guide before rollout.
- Review local user accounts and restrict unnecessary local logon rights.
- Re-check CISA KEV and public proof-of-concept status weekly.
Information from Microsoft (Patch Tuesday October 2026)
- Severity (Microsoft)
- Important
- Impact
- Elevation of privilege – Windows Clipboard Server
- Status on Patch Tuesday
- Neither exploited nor publicly disclosed
- Exploitability assessment
- Exploitation less likely
- Product family
- Windows, Windows ESU (Extended Security Updates)
- Updates (KB)
- KB5126651, KB5126655, KB5126657, KB5126646, KB5127648, KB5126653
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Microsoft Security Update Guide: CVE-2026-69795 msrc.microsoft.com
- Tenable plugin 365475 (Windows 10 1809 / Server 2019, October 2026) www.tenable.com
- Vulners CVELIST record CVE-2026-69795 vulners.com
- Vulners MSCVE record MS:CVE-2026-69795 vulners.com
- Vulners BDU:2026-17310 (FSTEC entry) vulners.com
- Vulners Rapid7 record RAPID7:CVE-2026-69795 (EPSS) 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, 09:34.
Original description (NVD)
Null pointer dereference in Windows Clipboard Server 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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