---
id: CVE-2020-1109
title: >-
  An elevation of privilege vulnerability exists when the Windows Update Stack
  fails to properly handle objects in memory
summary: >-
  An elevation of privilege vulnerability exists when the Windows Update Stack
  fails to properly handle objects in memory. An attacker who successfully
  exploited this vulnerability could run arbitrary code in kernel mode. An
  attacker could…
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
vendor: microsoft
product: windows_10
affected:
  - windows_10 = 1709
  - windows_10 = 1803
  - windows_10 = 1809
  - windows_10 = 1903
  - windows_10 = 1909
  - windows_server_2019
published: '2020-05-21'
updated: '2026-08-19'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2020-1109'
references:
  - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2020-1109'
    label: secure@microsoft.com
  - url: >-
      https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-1109
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.00981
epssPercentile: 0.60798
ingestedAt: '2026-08-19T17:42:38.284Z'
---

## Overview

An elevation of privilege vulnerability exists when the Windows Update Stack fails to properly handle objects in memory. An attacker who successfully exploited this vulnerability could run arbitrary code in kernel mode. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.
To exploit this vulnerability, an attacker would first have to log on to the system. An attacker could then run a specially crafted application to take control of an affected system.
The update addresses the vulnerability by correcting how the Windows Update Stack handles objects in memory.

## Affected

- `windows_10 = 1709`
- `windows_10 = 1803`
- `windows_10 = 1809`
- `windows_10 = 1903`
- `windows_10 = 1909`
- `windows_server_2019`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.