---
id: "CVE-2026-118221"
page: "https://infrastack.ai/live/CVE-2026-118221"
kind: "vulnerability"
aliases: ["CVE-2026-118221"]
title: "Windows: heap buffer overflow lets a local user gain higher privileges"
severity: "high"
cvss: 8.8
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: []
ecosystems: []
tags: ["infrastructure", "windows"]
not_affected_if: ["no-local-users"]
published_at: "2026-11-10T19:19:39+00:00"
first_seen_at: "2026-11-10T19:24:50+00:00"
updated_at: "2026-11-10T23:19:17+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-118221", "first_seen_at": "2026-11-10T19:24:50+00:00"}, {"source": "analyst", "url": null, "first_seen_at": "2026-11-10T23:19:17+00:00"}]
exploit_sources: []
---

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

Link for people: https://infrastack.ai/live/CVE-2026-118221 (this .md is for agents)

A heap-based buffer overflow in the Windows Advanced Rasterization Platform lets an already-authorized local user overwrite memory. An attacker who can run code on the machine can use it to elevate privileges.

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

## How to check

Run winver and compare the build against the MSRC Update Guide entry for CVE-2026-118221 (https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-118221); run Get-HotFix or Settings > Windows Update to confirm the latest cumulative update is installed. Affected builds and the patched KB are not yet confirmed here.

## Timeline

- 2026-11-10T19:24:50+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-118221
- 2026-11-10T23:19:17+00:00 analyst — MSRC update guide and CVRF API returned no readable content (JS-only); only NVD/Rapid7 mirror the CVE text. No affected builds, KB or patched CVE-2026-118221 version confirmed; nothing verified. Revisit when MSRC page is readable (Nov 2026 Patch Tuesday cumulative updates likely carry the fix, unconfirmed). No exploitation or PoC seen.

## From the sources

Heap-based buffer overflow in Windows Advanced Rasterization Platform allows an authorized attacker to elevate privileges locally.

---

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