Microsoft Windows Kernel: Elevation of privilege via out-of-bounds read
Summary
A local out-of-bounds read in the Windows Kernel allows an authorized attacker to elevate privileges on the affected system. The attacker needs a low-privileged account or foothold on the machine first, so the flaw is not directly reachable from the internet. Successful exploitation gives full control over the system, and attackers often combine such flaws with other vulnerabilities.
Affected
- Windows 11 Version 24H2: 10.0.26100.0 to before 10.0.26100.9711
- Windows 11 Version 25H2: 10.0.26200.0 to before 10.0.26200.9711
- Windows 11 Version 26H1: 10.0.28000.0 to before 10.0.28000.3231
- Windows 11 Version 26H2: 10.0.26300.0 to before 10.0.26300.9711
- Windows Server 2025 (including Server Core): 10.0.26100.0 to before 10.0.26100.33650
Fixed in
- Windows 11 Version 24H2: 10.0.26100.9711 (update released October 13, 2026; knowledge base number unknown, see MSRC)
- Windows 11 Version 25H2: 10.0.26200.9711
- Windows 11 Version 26H1: 10.0.28000.3231
- Windows 11 Version 26H2: 10.0.26300.9711
- Windows Server 2025: 10.0.26100.33650
Build numbers were taken from the CVE record and NVD data and should be verified on the MSRC advisory page.
Workaround
Unknown. No workaround is documented in the sources reviewed; the security update is the only confirmed fix.
Exploitation
- CISA SSVC: Exploitation none, Automatable no, Technical Impact total
- Microsoft temporal vector: exploit code maturity Unproven (E:U), report confidence Confirmed (RC:C)
- No public proof of concept or evidence of active exploitation found; absence not confirmed
- EPSS about 0.3%
Our recommendation
- Install the October 2026 security update on all Windows 11 24H2, 25H2, 26H1, 26H2 and Windows Server 2025 systems, prioritising servers and shared or multi-user systems such as terminal servers.
- Verify the installed build against the MSRC advisory before relying on it.
- Restrict local logon rights and remove unnecessary local user accounts.
- Monitor endpoints for suspicious privilege escalation and unexpected processes.
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 Response Center: CVE-2026-85837 msrc.microsoft.com
- NVD record via Vulners vulners.com
- OpenCVE: CVE-2026-85837 app.opencve.io
- VulDB: CVE-2026-85837 vuldb.com
- Strix: CVE-2026-85837 www.strix.ai
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, 02:04.
Original description (NVD)
Out-of-bounds read in Windows Kernel 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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