Windows Kernel: Elevation of privilege due to integer underflow
Summary
An integer underflow in the Windows kernel allows an attacker to elevate privileges on affected Windows systems. Microsoft rates the flaw Important with a CVSS 3.1 base score of 6.8 (MEDIUM). According to the CVSS vector and the description, the attacker needs physical access to the device and no privileges, and the exact trigger conditions are not publicly documented.
Affected
- Windows 10 Version 1607 (builds before 10.0.14393.9688)
- Windows 10 Version 1809 (builds before 10.0.17763.9487)
- Windows 10 Version 21H2 (builds before 10.0.19044.7846)
- Windows 10 Version 22H2 (builds before 10.0.19045.7846)
- Windows 11 Version 23H2 (builds before 10.0.22631.7711)
- Windows 11 Version 24H2 (builds before 10.0.26100.9974)
- Windows 11 Version 25H2 (builds before 10.0.26200.9974)
- Windows 11 Version 26H1 (builds before 10.0.28000.3501)
- Windows 11 Version 26H2 (builds before 10.0.26300.9974)
- Windows Server 2016 and Server Core installation (builds before 10.0.14393.9688)
- Windows Server 2019 and Server Core installation (builds before 10.0.17763.9487)
- Windows Server 2022 (builds before 10.0.20348.5870)
Fixed in
- Install the Microsoft security update of November 2026 (cumulative update) for your Windows version, which brings the build numbers above the thresholds listed under affected.
- KB numbers: Unknown.
Workaround
- No vendor workaround known.
- Physical controls reduce the risk until patching: locked screens, no unattended sessions, device encryption and BIOS/UEFI passwords.
Exploitation
- No evidence of exploitation in the wild found.
- No public proof of concept found.
- Microsoft's SSVC assessment: exploitation none, not automatable, technical impact total.
- CISA KEV status: Unknown.
Our recommendation
- Deploy the November 2026 cumulative update through your normal Patch Tuesday cycle, prioritising laptops, travelling devices and shared workstations.
- Replace or upgrade Windows 10 1607, 1809 and 21H2 systems that are out of support or cannot receive the update.
- Enable full-disk encryption, automatic screen locking and BIOS/UEFI passwords on endpoints.
- Verify the affected builds on your systems against the MSRC advisory.
Information from Microsoft (Patch Tuesday November 2026)
- Severity (Microsoft)
- Important
- Impact
- Elevation of privilege – Windows Kernel
- Status on Patch Tuesday
- Neither exploited nor publicly disclosed
- Exploitability assessment
- Exploitation unlikely
- Product family
- Windows, Windows ESU (Extended Security Updates)
- Updates (KB)
- KB5131085, KB5131096, KB5131090, KB5131087, KB5132061, KB5132043
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Microsoft Security Update Guide: CVE-2026-119935 msrc.microsoft.com
- CVE Record CVE-2026-119935 (CNA: Microsoft) www.cve.org
- BleepingComputer: Microsoft November 2026 Patch Tuesday www.bleepingcomputer.com
- Rapid7: Patch Tuesday November 2026 www.rapid7.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 11 Nov 2026, 10:35.
Original description (NVD)
Integer underflow (wrap or wraparound) in Windows Kernel allows an unauthorized attacker to elevate privileges with a physical attack.
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.
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