Microsoft Windows: Use-after-free in Kernel Streaming Service driver
Summary
A use-after-free vulnerability (CWE-416) in the Windows Kernel Streaming Service driver allows an authorized local attacker to elevate privileges. According to Microsoft, a successful attacker could gain SYSTEM privileges. The attacker needs an existing local foothold and low privileges, and exploitation is rated as highly complex; the flaw is not remotely exploitable.
Affected
- Windows 10 Version 1607 (builds below 10.0.14393.9612)
- 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 2012 and 2012 R2 (see Microsoft advisory for builds)
- Windows Server 2016 (builds below 10.0.14393.9612)
Fixed in
- Windows 10 Version 1607: build 10.0.14393.9612
- Other affected versions: fixed builds as listed in the Microsoft Security Update Guide
- KB number for Windows 10 Version 1607: Unknown. Check the Microsoft Security Update Guide.
Workaround
None documented. Install the security update.
Exploitation
- CISA SSVC: Exploitation none, Automatable no, Technical Impact total
- Not listed in the CISA KEV catalog according to the OpenCVE record
- No public proof-of-concept found
- EPSS 0.00242 (low)
- No known exploitation in the wild
Our recommendation
- Install the Microsoft security update that brings Windows 10 Version 1607 to build 10.0.14393.9612 or later. Check the MSRC page for the KB number.
- If Windows 10 Version 1607 hosts remain, check the Microsoft lifecycle page for support status and plan an upgrade if support has ended.
- Restrict local logon and limit local administrator rights to reduce the risk of a local foothold.
- Monitor affected hosts for unusual privilege changes and unexpected SYSTEM processes.
Information from Microsoft (Patch Tuesday October 2026)
- Severity (Microsoft)
- Important
- Impact
- Elevation of privilege – Microsoft Streaming Service
- Status on Patch Tuesday
- Neither exploited nor publicly disclosed
- Exploitability assessment
- Exploitation unlikely
- 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-2026-69964 msrc.microsoft.com
- Vulners NVD record: CVE-2026-69964 vulners.com
- Vulners CVE List record (Microsoft CNA data): CVE-2026-69964 vulners.com
- Vulners MSCVE record: MS:CVE-2026-69964 vulners.com
- OpenCVE: CVE-2026-69964 app.opencve.io
- VulDB: CVE-2026-69964 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, 09:28.
Original description (NVD)
Use after free in Microsoft Streaming Service 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.
Affected? We can help.
We check whether your systems are affected, install updates and close the gap – continuously with the System Health Checker if you wish.