# CVE-2021-40449: Microsoft Windows Win32k Privilege Escalation Vulnerability

Source: https://junglewise.ai/threats/cve-2021-40449-microsoft-windows-win32k-privilege-escalation-vulnerability  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2021-11-17. Updated: 2026-05-10  
License: CC BY 4.0 with a link back

CVE-2021-40449 · Severity: critical · CVSS 7.8 · Exploited in the wild · Published 2021-11-17

A use-after-free vulnerability in the Windows Win32k component (specifically involving NtGdiResetDC) allows an authenticated local attacker to escalate privileges. The vulnerability has been observed being exploited in the wild.

Technologies: [Microsoft Windows](https://junglewise.ai/threats/technologies/windows). Vendors: [Microsoft](https://junglewise.ai/threats/vendors/microsoft).

## Quick answers

**Is CVE-2021-40449 exploited in the wild?** Yes. CVE-2021-40449 is known to be exploited in the wild, first recorded on 17 November 2021. Treat it as urgent.

**How severe is CVE-2021-40449?** Critical severity, with a CVSS score of 7.8, published 17 November 2021.

**Which products and versions are affected?** Microsoft Windows 10 up to (excluding) 10.0.10240.19086; Microsoft Windows 11 up to (excluding) 10.0.22000.258; Microsoft Windows Server 2022 up to (excluding) 10.0.20348.288; Microsoft Windows 7 SP1; and 5 more.

**Is there a fix for CVE-2021-40449?** A patch was published on 2021-11-17. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2021-40449 attacked?** It is attacked with local access, in an operating system.

**Am I affected by CVE-2021-40449?** Check whether you run Microsoft Windows. 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 Windows 10 up to (excluding) 10.0.10240.19086
- Microsoft Windows 11 up to (excluding) 10.0.22000.258
- Microsoft Windows Server 2022 up to (excluding) 10.0.20348.288
- Microsoft Windows 7 SP1
- Microsoft Windows 8.1
- Microsoft Windows Server 2008
- Microsoft Windows Server 2012
- Microsoft Windows Server 2016
- Microsoft Windows Server 2019

## Timeline

- 2021-11-17: disclosed
- 2021-11-17: kev added: Added to CISA Known Exploited Vulnerabilities Catalog
- 2021-11-17: patched

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