What is the CVSS score of CVE-2021-42278?

CVE-2021-42278 has a CVSS 3.1 base score of 7.5 (High). CVSS vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 70.2%.

Is CVE-2021-42278 being actively exploited?

Yes, CVE-2021-42278 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, confirming active in-the-wild exploitation. Immediate patching is required.

Is there a patch available for CVE-2021-42278?

Yes, a patch is available for CVE-2021-42278. Update the affected software to the latest version immediately.

Windows Server 2004 CVE-2021-42278

HIGH

2021-11-10 secure@microsoft.com

Information Disclosure Windows Server 2004 Windows Server 2008 Windows Server 2012 Windows Server 2016 Windows Server 2019 Windows Server 2022 Windows Server 20H2

7.5

CVSS 3.1 · Vendor: microsoft

Severity by source

Vendor (microsoft) PRIMARY

7.5 HIGH

AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Primary rating from Vendor (microsoft) · only source for this CVE.

CVSS VectorVendor: microsoft

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack Vector

Network

Attack Complexity

High

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Added to CISA KEV

Jul 14, 2026 - 04:22 CISA

CVE Published

Nov 10, 2021 - 01:19 cve.org

HIGH 7.5

DescriptionCVE.org

Active Directory Domain Services Elevation of Privilege Vulnerability

AnalysisAI

Active Directory Domain Services Elevation of Privilege Vulnerability. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable.

Technical ContextAI

Active Directory Domain Services Elevation of Privilege Vulnerability Affected products include: Microsoft Windows Server 2004, Microsoft Windows Server 2008, Microsoft Windows Server 2012, Microsoft Windows Server 2016, Microsoft Windows Server 2019.

RemediationAI

A vendor patch is available. Apply the latest security update as soon as possible. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.

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CVE-2021-42278 vulnerability details – vuln.today

Back

Windows Server 2004 CVE-2021-42278

Severity by source

CVSS VectorVendor: microsoft

Lifecycle Timeline

DescriptionCVE.org

AnalysisAI

Technical ContextAI

RemediationAI

More in Windows Server 2004

Same technique Information Disclosure

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External POC / Exploit Code