---
id: CVE-2020-1064
title: >-
  A remote code execution vulnerability exists in the way that the MSHTML engine
  improperly validates input.

  An attacker could execute arbitrary code in the context of the current user
summary: >-
  A remote code execution vulnerability exists in the way that the MSHTML engine
  improperly validates input.

  An attacker could execute arbitrary code in the context of the current user.
  If the current user is logged on with administrative …
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H'
vendor: microsoft
product: internet_explorer
affected:
  - internet_explorer = 9
  - internet_explorer = 11
published: '2020-05-21'
updated: '2026-08-19'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2020-1064'
references:
  - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2020-1064'
    label: secure@microsoft.com
  - url: >-
      https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-1064
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.0314
epssPercentile: 0.87358
ingestedAt: '2026-08-19T17:42:36.789Z'
---

## Overview

A remote code execution vulnerability exists in the way that the MSHTML engine improperly validates input.
An attacker could execute arbitrary code in the context of the current user. If the current user is logged on with administrative user rights, an attacker who successfully exploited the vulnerability could take control of an affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.
In a HTML editing attack scenario, an attacker could trick a user into editing a specially crafted file that is designed to exploit the vulnerability.
The security update addresses the vulnerability by modifying how MSHTML engine validates input.

## Affected

- `internet_explorer = 9`
- `internet_explorer = 11`

## Remediation

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