---
id: CVE-2021-26411
title: Internet Explorer Memory Corruption Vulnerability
summary: Internet Explorer Memory Corruption Vulnerability
severity: high
cvss: 8.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:L'
cwe:
  - CWE-416
  - CWE-416
vendor: microsoft
product: edge
affected:
  - edge
  - internet_explorer = 11
  - internet_explorer = 9
published: '2021-03-11'
updated: '2026-08-12'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2021-26411'
references:
  - url: >-
      https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26411
    label: secure@microsoft.com
  - url: >-
      https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26411
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-26411
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
  - kev
  - in-the-wild
  - exploit-available
epss: 0.80765
epssPercentile: 0.99617
kev: true
kevDateAdded: '2021-11-03'
kevDueDate: '2021-11-17'
kevRansomware: true
exploited: true
zeroDay: true
ingestedAt: '2026-08-12T19:54:25.780Z'
exploits:
  github: 1
  githubRepos:
    - 'https://github.com/CrackerCat/CVE-2021-26411'
  checkedAt: '2026-09-25T08:20:38.428Z'
exploitAvailable: true
---

## Overview

Internet Explorer Memory Corruption Vulnerability

## Affected

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

## Remediation

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