# CVE-2021-28310: Microsoft Win32k Privilege Escalation Vulnerability

Source: https://junglewise.ai/threats/cve-2021-28310-microsoft-win32k-privilege-escalation-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-2021-28310 · Severity: critical · CVSS 7.8 · Exploited in the wild · Published 2021-11-03

A privilege escalation vulnerability exists in the Microsoft Windows Win32k component due to an out-of-bounds write (CWE-787). An attacker who successfully exploits this vulnerability could gain elevated system privileges. This vulnerability has been observed being exploited in the wild.

Technologies: [Microsoft Win32K](https://junglewise.ai/threats/technologies/win32k). Vendors: [Microsoft](https://junglewise.ai/threats/vendors/microsoft).

## Quick answers

**Is CVE-2021-28310 exploited in the wild?** Yes. CVE-2021-28310 is known to be exploited in the wild, first recorded on 3 November 2021. Treat it as urgent.

**How severe is CVE-2021-28310?** Critical severity, with a CVSS score of 7.8, published 3 November 2021.

**Which products and versions are affected?** Microsoft Windows 10 1803, 1809, 1909, 2004, 20H2; Microsoft Windows Server 1909, 2004, 20H2, 2019.

**Is there a fix for CVE-2021-28310?** A patch was published on 2021-04-13: Microsoft released security updates Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2021-28310 attacked?** It is attacked with local access, in an operating system.

**Am I affected by CVE-2021-28310?** Check whether you run Microsoft Win32K. 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 1803, 1809, 1909, 2004, 20H2
- Microsoft Windows Server 1909, 2004, 20H2, 2019

## Timeline

- 2021-04-13: disclosed: NVD Published Date
- 2021-04-13: patched: Microsoft released security updates
- 2021-11-03: kev added: Added to CISA Known Exploited Vulnerabilities Catalog
- 2021-11-03: exploited: Confirmed exploited in the wild per CISA KEV catalog entry date

## Related threats

- [Microsoft Win32k Privilege Escalation Vulnerability](https://junglewise.ai/threats/cve-2016-0165-microsoft-win32k-privilege-escalation-vulnerability)
- [Microsoft Win32K Privilege Escalation Vulnerability](https://junglewise.ai/threats/cve-2023-29336-microsoft-win32k-privilege-escalation-vulnerability)
- [Microsoft Win32k Privilege Escalation Vulnerability](https://junglewise.ai/threats/cve-2015-2360-microsoft-win32k-privilege-escalation-vulnerability)
- [Microsoft Win32k Privilege Escalation Vulnerability](https://junglewise.ai/threats/cve-2018-8589-microsoft-win32k-privilege-escalation-vulnerability)
- [Microsoft Win32k Privilege Escalation Vulnerability](https://junglewise.ai/threats/cve-2014-4113-microsoft-win32k-privilege-escalation-vulnerability)