Is CVE-2021-28310 actively exploited?

Yes. KEV Intelligence tracks CVE-2021-28310 as a known exploited vulnerability. Confidence is confirmed.

What exploitation activity has KEV Intelligence observed?

KEV Intelligence has not yet recorded sensor-observed exploitation attempts for CVE-2021-28310. Our sensors continue to monitor for activity targeting this CVE.

Which versions are affected?

CVE-2021-28310 affects Microsoft Windows 10 Version 1803 and 10 other products. KEV Intelligence lists 10 version rows; examples include 10.0.0 to < publication.

Yes. CVE-2021-28310 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

CVE-2021-28310 Exploited in the Wild — Windows 10 Version 1803, Windows 10 Version 1809, Windows Server 2019, Windows Server 2019 (Server Core installation), Windows 10 Version 1909, Windows Server, version 1909 (Server Core installation), Windows 10 Version 2004, Windows Server version 2004, Windows 10 Version 20H2, Windows Server version 20H2

Q: What is CVE-2021-28310?

CVE-2021-28310 is Win32k Elevation of Privilege Vulnerability affecting Microsoft Windows 10 Version 1803 and 10 other products.

Q: How should organizations remediate it?

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

Q: Is it in CISA KEV?

Yes. CVE-2021-28310 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2021-28310 is Win32k Elevation of Privilege Vulnerability affecting Microsoft Windows 10 Version 1803 and 10 other products.

Is it exploited?

Yes. KEV Intelligence tracks this CVE as a known exploited vulnerability. Confidence is confirmed.

Who is affected?

Microsoft / Windows 10 Version 1803 affected before publication.

What should we do?

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

Overview

Win32k Elevation of Privilege Vulnerability

Vendor Product Affected Status

Microsoft Windows 10 Version 1803 Before publication Affected

Microsoft Windows 10 Version 1809 Before publication Affected

Microsoft Windows Server 2019 Before publication Affected

Microsoft Windows Server 2019 (Server Core installation) Before publication Affected

Microsoft Windows 10 Version 1909 Before publication Affected

Microsoft Windows Server, version 1909 (Server Core installation) Before publication Affected

Microsoft Windows 10 Version 2004 Before publication Affected

Microsoft Windows Server version 2004 Before publication Affected

Microsoft Windows 10 Version 20H2 Before publication Affected

Microsoft Windows Server version 20H2 Before publication Affected

Published: 13 Apr 2021
Exploitation Reported: 03 Nov 2021
Attack vector: Local
Complexity: Low
Privileges: Low
User interaction: None

CVE References

CVE Record CVE.org · CVE Record https://www.cve.org/CVERecord?id=CVE-2021-28310
portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-28310 portal.msrc.microsoft.com · CVE Record https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CV...

Exploitation evidence

Why KEV Intelligence marks this CVE as exploited

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploited in the wild

CISA

Recorded 03 Nov 2021

Independent exploitation attestation added to the KEV Intelligence record.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the KEV Intelligence Pro API.

Learn about Pro API access

Source	Added
CISA First	2021-11-03 00:00 UTC

Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Observed signals

Request targets: 0
User-Agents: 0

Raw values available in Pro and Enterprise.

Scanner coverage

No scanner integrations recorded yet.

Virtual patch status

No KEV Intelligence virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

Learn about virtual patches →

No detection artifacts or sensor request patterns are available for this CVE yet.

Check back as sensor telemetry and scanner integrations are updated.

Risk and context

Severity, weaknesses, and research context

CVSS v3.1

7.8 High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C

EPSS

8.3%

Weaknesses

Out-of-bounds Write CWE-787

Timeline

From disclosure to observed exploitation

03 Nov 2021
Added to CISA KEV

Listed in the CISA Known Exploited Vulnerabilities catalog
13 Apr 2021
CVE published

Vulnerability disclosed publicly
12 Mar 2021
CVE ID reserved

Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

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Evidence confidence and provenance
First-party sensor telemetry
PoC and scanner references
Affected versions and enrichment
Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2021-28310

Free JSON includes basic KEV fields

{
  "cve_id": "CVE-2021-28310",
  "confidence": "Confirmed",
  "cvss_score": 7.8,
  "cvss_estimated": false,
  "epss_score": 0.0833,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": false
  },
  "sensor_telemetry": { "attempts": 0, "sensors": 0 }
}

CVE-2021-28310