# CVE-2021-26411: Microsoft Internet Explorer Memory Corruption Vulnerability

Source: https://junglewise.ai/threats/cve-2021-26411-microsoft-internet-explorer-memory-corruption-vulnerability  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2021-11-03. Updated: 2026-05-10  
License: CC BY 4.0 with a link back

CVE-2021-26411 · Severity: critical · CVSS 8.8 · Exploited in the wild · Published 2021-11-03

A memory corruption vulnerability exists in Microsoft Internet Explorer due to a use-after-free (CWE-416) error. An attacker can exploit this by convincing a user to visit a specially crafted website, potentially leading to remote code execution.

Technologies: [Microsoft Internet Explorer](https://junglewise.ai/threats/technologies/internet-explorer). Vendors: [Microsoft](https://junglewise.ai/threats/vendors/microsoft).

## Quick answers

**Is CVE-2021-26411 exploited in the wild?** Yes. CVE-2021-26411 is known to be exploited in the wild, first recorded on 3 November 2021. Treat it as urgent.

**How severe is CVE-2021-26411?** Critical severity, with a CVSS score of 8.8, published 3 November 2021.

**Which products and versions are affected?** Microsoft Internet Explorer 11; Microsoft Edge; Microsoft Windows 10; Microsoft Windows 7; and 4 more.

**Is there a fix for CVE-2021-26411?** A patch was published on 2021-11-03: Microsoft released security updates to address this vulnerability. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2021-26411 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2021-26411?** Check whether you run Microsoft Internet Explorer. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Affected products

- Microsoft Internet Explorer 11
- Microsoft Edge
- Microsoft Windows 10
- Microsoft Windows 7
- Microsoft Windows 8.1
- Microsoft Windows Server 2012
- Microsoft Windows Server 2016
- Microsoft Windows Server 2019

## Timeline

- 2021-11-03: disclosed
- 2021-11-03: kev added: Added to CISA Known Exploited Vulnerabilities Catalog
- 2021-11-03: patched: Microsoft released security updates to address this vulnerability.

## Related threats

- [Microsoft Internet Explorer use-after-free privilege escalation](https://junglewise.ai/threats/cve-2026-83741-use-after-free-in-internet-explorer-allows-an-authorized-attacker)
- [Microsoft Internet Explorer use-after-free in HTML object handling](https://junglewise.ai/threats/cve-2010-0249-microsoft-internet-explorer-use-after-free-in-html-object-handling)
- [Microsoft Internet Explorer use-after-free in Peer Objects](https://junglewise.ai/threats/cve-2010-0806-microsoft-internet-explorer-use-after-free-in-peer-objects)
- [Microsoft Internet Explorer use-after-free in CSS processing](https://junglewise.ai/threats/cve-2010-3962-microsoft-internet-explorer-use-after-free-in-css-processing)
- [Microsoft Internet Explorer use after free in mshtml.dll](https://junglewise.ai/threats/cve-2013-3893-microsoft-internet-explorer-use-after-free-in-mshtml-dll)