CVE-2020-16996: Kerberos Security Feature Bypass Vulnerability

Severity: medium (CVSS 4.0 v2.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 2.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2020-12-09 · updated 2026-06-17

Description

Kerberos Security Feature Bypass Vulnerability

Affected products

Microsoft Windows Server 2012: r2
Microsoft Windows Server 2016: 20h2, 1903, 1909, 2004
Microsoft Windows Server 2019: all versions
Microsoft Windows Server 2012: from 6.2.9200.0 before 6.2.9200.23298 — fixed in 6.2.9200.23298
Microsoft Windows Server 2012 R2: from 6.3.9600.0 before 6.3.9600.19968 — fixed in 6.3.9600.19968
Microsoft Windows Server 2016: from 10.0.14393.0 before 10.0.14393.4283 — fixed in 10.0.14393.4283
Microsoft Windows Server 2019: from 10.0.17763.0 before 10.0.17763.1817 — fixed in 10.0.17763.1817
Microsoft Windows Server, version 1903 (Server Core installation): from 10.0.0 before publication — fixed in publication
Microsoft Windows Server, version 1909 (Server Core installation): from 10.0.0 before 10.0.18363.1440 — fixed in 10.0.18363.1440
Microsoft Windows Server version 2004: from 10.0.0 before 10.0.19043.867 — fixed in 10.0.19043.867
Microsoft Windows Server version 20H2: from 10.0.0 before 10.0.19043.867 — fixed in 10.0.19043.867

How to fix

Upgrade to a fixed version: Microsoft Windows Server 2012 6.2.9200.23298; Microsoft Windows Server 2012 R2 6.3.9600.19968; Microsoft Windows Server 2016 10.0.14393.4283; Microsoft Windows Server 2019 10.0.17763.1817; Microsoft Windows Server, version 1903 (Server Core installation) publication; Microsoft Windows Server, version 1909 (Server Core installation) 10.0.18363.1440; Microsoft Windows Server version 2004 10.0.19043.867; Microsoft Windows Server version 20H2 10.0.19043.867. Check the vendor advisory for mitigations.

References

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