Windows Input System: Heap-based buffer overflow enables privilege escalation
Summary
The Windows Input System component in multiple Windows 10, Windows 11 and Windows Server versions contains a heap-based buffer overflow (CWE-122). An authorized local attacker with low privileges can exploit it to elevate privileges, potentially up to SYSTEM level. The attacker needs an existing local session on the affected system, and no user interaction is required. The CVSS score is 8.8 (HIGH) with a scope change and high impact on confidentiality, integrity and availability.
Affected
- Windows 10 Version 1809: 10.0.17763.0 to before 10.0.17763.9487
- Windows 10 Version 21H2: 10.0.19044.0 to before 10.0.19044.7846
- Windows 10 Version 22H2: 10.0.19045.0 to before 10.0.19045.7846
- Windows 11 Version 23H2: 10.0.22631.0 to before 10.0.22631.7711
- Windows 11 Version 24H2: 10.0.26100.0 to before 10.0.26100.9974
- Windows 11 Version 25H2: 10.0.26200.0 to before 10.0.26200.9974
- Windows 11 Version 26H1: 10.0.28000.0 to before 10.0.28000.3501
- Windows 11 Version 26H2: 10.0.26300.0 to before 10.0.26300.9974
- Windows Server 2019 (including Server Core): 10.0.17763.0 to before 10.0.17763.9487
- Windows Server 2022: 10.0.20348.0 to before 10.0.20348.5870
- Windows Server 2025 (including Server Core): 10.0.26100.0 to before 10.0.26100.33822
Fixed in
- Install the Microsoft security update for CVE-2026-119916 that brings the build to the listed fixed version or higher (see the MSRC Security Update Guide for the matching KB numbers).
Workaround
Unknown.
Exploitation
- No known exploitation at the time of publication.
- CISA SSVC assessment: Exploitation none, Automatable no, Technical Impact total.
Our recommendation
- Apply the Microsoft security update for CVE-2026-119916 to all affected Windows 10, Windows 11 and Windows Server systems, prioritising systems that allow local user logons.
- Confirm the affected products, KB numbers and exploitability on the MSRC page, as the NVD entry was still awaiting analysis at publication.
- Restrict local logons to trusted users and monitor for unexpected privilege escalation or SYSTEM-level processes.
Information from Microsoft (Patch Tuesday November 2026)
- Severity (Microsoft)
- Important
- Impact
- Elevation of privilege – Windows Input System
- Status on Patch Tuesday
- Neither exploited nor publicly disclosed
- Exploitability assessment
- Exploitation less likely
- Product family
- Windows, Windows ESU (Extended Security Updates)
- Updates (KB)
- KB5131085, KB5131090, KB5131096, KB5131080, KB5131077, KB5132061
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Microsoft Security Update Guide: CVE-2026-119916 msrc.microsoft.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 10 Nov 2026, 20:25.
Original description (NVD)
Heap-based buffer overflow in Windows Input System 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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