---
id: "CVE-2026-119861"
page: "https://infrastack.ai/live/CVE-2026-119861"
kind: "vulnerability"
aliases: ["CVE-2026-119861"]
title: "Windows ICS: heap overflow lets a local user gain higher privileges"
severity: "high"
cvss: 7.0
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: [{"name": "Windows", "fixed": ["November 2026 cumulative update"], "affected": "Windows 10 1607-22H2, Windows 11 23H2-26H2, Windows Server 2016-2025", "ecosystem": "microsoft"}]
ecosystems: []
tags: ["infrastructure", "internet-connection-sharing", "local-privilege-escalation", "windows"]
not_affected_if: ["ics-not-enabled"]
published_at: "2026-11-10T19:20:04+00:00"
first_seen_at: "2026-11-10T19:25:00+00:00"
updated_at: "2026-11-10T22:46:01+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-119861", "first_seen_at": "2026-11-10T19:25:00+00:00"}, {"source": "analyst", "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-119861", "first_seen_at": "2026-11-10T22:46:01+00:00", "cites": ["https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-119861"]}]
exploit_sources: []
---

# Windows ICS: heap overflow lets a local user gain higher privileges

Link for people: https://infrastack.ai/live/CVE-2026-119861 (this .md is for agents)

Heap-based buffer overflow (CWE-416 use-after-free per Microsoft) in Windows Internet Connection Sharing lets a local, low-privileged attacker gain SYSTEM. Exploitation needs winning a race condition. Microsoft rates it Important (CVSS 7.0), not publicly disclosed, not exploited, 'Exploitation Less Likely'. Published in the November 2026 Patch Tuesday.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- microsoft:Windows affected Windows 10 1607-22H2, Windows 11 23H2-26H2, Windows Server 2016-2025 fixed November 2026 cumulative update

## How to check

Check that the November 2026 (2026-Nov) cumulative update for your Windows version is installed (Settings > Windows Update > Update history, or Get-HotFix). The exact KB per build is listed on the MSRC page for CVE-2026-119861, which did not expose it in the data I could read. Microsoft does not state whether ICS must be enabled; also check whether the SharedAccess service is running (Get-Service SharedAccess) to judge priority, but treat all listed builds as exposed until patched.

## Fix

Install the November 2026 Windows security update for your build. KB numbers: unknown, see the MSRC page.

## Timeline

- 2026-11-10T19:25:00+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-119861
- 2026-11-10T22:46:01+00:00 analyst https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-119861 — Read MSRC SUG API record and NVD API; no KB numbers/build numbers in either, so fix left unknown. Not exploited, not public, Exploitation Less Likely. X/search not used (B tier, local EoP, nothing to find).

## Documents

- [advisory] MSRC: Windows ICS Elevation of Privilege Vulnerability CVE-2026-119861 https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-119861

## From the sources

Heap-based buffer overflow in Windows Internet Connection Sharing (ICS) allows an authorized attacker to elevate privileges locally.

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_Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai_