Windows: Use-after-free in Spaceport.sys allows local privilege escalation
Summary
A use-after-free vulnerability in the Windows kernel-mode driver Spaceport.sys allows an authorized local user to elevate privileges. An attacker needs valid low-privilege access to the system and no user interaction is required. Successful exploitation could grant SYSTEM rights, which is most relevant on shared, multi-user and remote-session systems.
Affected
- Windows 10 Version 1809: 10.0.17763.0 to below 10.0.17763.9376
- Windows Server 2019 (including Server Core): 10.0.17763.0 to below 10.0.17763.9376
- Other affected Windows client and server versions are listed in the CNA record (for example Windows 10 21H2 and 22H2, Windows 11, Windows Server 2022 and 2025).
Fixed in
- Windows 10 Version 1809 and Windows Server 2019: 10.0.17763.9376 or later (CNA record)
- Windows 10 21H2: 10.0.19044.7807 or later (CNA record)
- Windows 10 22H2: 10.0.19045.7807 or later (CNA record; a third-party tracker lists a different value, so verify on MSRC)
- A third-party source references KB5126651 for Windows 10 1809 and Server 2019; this KB number has not been verified.
Workaround
Unknown. No workaround was found in the sources. Check the MSRC advisory for any published interim mitigation.
Exploitation
- No known exploitation in the wild at the time of research.
- CISA SSVC: exploitation none, automatable no, technical impact total.
- Not listed in CISA KEV. EPSS: 0.00341.
- Public proof-of-concept code was not checked.
Our recommendation
- Install the October 2026 security update on affected Windows 10 1809 and Windows Server 2019 systems, prioritising multi-user, terminal and RDS hosts.
- Confirm the fixed build numbers on the MSRC page before deployment.
- Check whether your Windows 10 1809 systems still receive security updates; if not, plan an upgrade.
- Review local accounts and restrict local logon on shared systems.
- Monitor for suspicious privilege escalation on affected hosts.
Information from Microsoft (Patch Tuesday October 2026)
- Severity (Microsoft)
- Important
- Impact
- Elevation of privilege – Windows Spaceport.sys
- 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, KB5126657, KB5126655, KB5126653, KB5127648, KB5126646
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Microsoft Security Update Guide: CVE-2026-70102 msrc.microsoft.com
- Vulners CVE list record CVE-2026-70102 vulners.com
- Vulners Microsoft CVE record MS:CVE-2026-70102 vulners.com
- Vulners NVD record CVE-2026-70102 vulners.com
- OpenCVE CVE-2026-70102 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, 04:17.
Original description (NVD)
Use after free in Windows Spaceport.sys 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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