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CVE record · CVE-2021-26897

Windows DNS Server Remote Code Execution Vulnerability

CVSS 9.8 CriticalCriticalEPSS 0.12 · 96th percentile

Critical, because:

  • CVSS score 9.8: 9.0 or more.
  • CVSS score 9.8 (7.0 or more) and EPSS 0.12 (0.1 or more): a high score and a real chance of exploitation in the next 30 days.

How we decide what’s critical

Published by the CVE Program (CNA: microsoft) at 11 Mar 2021, 15:43 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it.

Affected products, as the CNA wrote them
VendorProductVersions
Microsoft Windows Server 2008 R2 Service Pack 1
  • affected 6.1.7601.0 to before 6.1.7601.24566 custom
Microsoft Windows Server 2008 R2 Service Pack 1 (Server Core installation)
  • affected 6.1.7601.0 to before 6.1.7601.24566 custom
Microsoft Windows Server 2008 Service Pack 2
  • affected 6.0.6003.0 to before 6.0.6003.21070 custom
Microsoft Windows Server 2008 Service Pack 2 (Server Core installation)
  • affected 6.0.6003.0 to before 6.0.6003.21070 custom
Microsoft Windows Server 2012
  • affected 6.2.9200.0 to before 6.2.9200.23298 custom
Microsoft Windows Server 2012 (Server Core installation)
  • affected 6.2.9200.0 to before 6.2.9200.23298 custom
Microsoft Windows Server 2012 R2
  • affected 6.3.9600.0 to before 6.3.9600.19968 custom
Microsoft Windows Server 2012 R2 (Server Core installation)
  • affected 6.3.9600.0 to before 6.3.9600.19968 custom
Microsoft Windows Server 2016
  • affected 10.0.14393.0 to before 10.0.14393.4283 custom
Microsoft Windows Server 2016 (Server Core installation)
  • affected 10.0.14393.0 to before 10.0.14393.4283 custom
Microsoft Windows Server 2019
  • affected 10.0.17763.0 to before 10.0.17763.1817 custom
Microsoft Windows Server 2019 (Server Core installation)
  • affected 10.0.17763.0 to before 10.0.17763.1817 custom
Microsoft Windows Server version 2004
  • affected 10.0.0 to before 10.0.19043.867 custom
Microsoft Windows Server version 20H2
  • affected 10.0.0 to before 10.0.19043.867 custom
Microsoft Windows Server, version 1909 (Server Core installation)
  • affected 10.0.0 to before 10.0.18363.1440 custom
Identifiers
CVE-2021-26897
CNA
microsoft
Tags
Published
11 Mar 2021
Updated
19 Aug 2026

Not analysed yet

We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter.

Severity and exploitation

ScoreRatingCVSSVectorSource
9.8 Critical 3.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C CNA (microsoft)
  • CISA KEV Not listed.
  • EPSS 0.12, the 96th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

This record came from the full history of the CVE Program, published 11 Mar 2021. New records show when each source confirmed them.

Sources

References from the CNA

Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description.