How severe is CVE-2021-31955?

CVE-2021-31955 has a CVSS 3.1 base score of 5.5 (MEDIUM). EPSS estimates a 81.1% probability of exploitation in the next 30 days. It is listed in the CISA Known Exploited Vulnerabilities catalog.

CVE-2021-31955: Windows Kernel Information Disclosure

CISA Known Exploited Vulnerabilities

Microsoft Windows Kernel Information Disclosure Vulnerability is confirmed as actively exploited and is listed in the CISA KEV catalog.

Added to KEV

2021-11-03

Remediation due

2021-11-17

Required action
Apply updates per vendor instructions.

CISA notes
https://nvd.nist.gov/vuln/detail/CVE-2021-31955

Description

Windows Kernel Information Disclosure Vulnerability

Severity

CVSS 3.1 · CNA5.5 MEDIUM

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

SSVC · CISA-ADP

Exploitationactive

Automatableno

Technical impactpartial

Affected Products

Vendor	Product	Affected versions
Microsoft	Windows 10 Version 1809	10.0.0 to <10.0.17763.1999
Microsoft	Windows Server 2019	10.0.0 to <10.0.17763.1999
Microsoft	Windows Server 2019 (Server Core installation)	10.0.0 to <10.0.17763.1999
Microsoft	Windows 10 Version 1909	10.0.0 to <10.0.18363.1621
Microsoft	Windows 10 Version 21H1	10.0.0 to <10.0.19043.1052
Microsoft	Windows 10 Version 2004	10.0.0 to <10.0.19041.1052
Microsoft	Windows Server version 2004	10.0.0 to <10.0.19041.1052
Microsoft	Windows 10 Version 20H2	10.0.0 to <10.0.19042.1052
Microsoft	Windows Server version 20H2	10.0.0 to <10.0.19042.1052

References

1 Links

Other references

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31955

Record Details

Published

2021-06-08

Last updated

2025-10-21

Assigner (CNA)

microsoft

Credited to

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CVE record data © The MITRE Corporation, used under the CVE Terms of Use. Exploited-in-the-wild data from the CISA Known Exploited Vulnerabilities catalog (CC0). Exploit prediction scores by FIRST EPSS (first.org/epss). This site is not endorsed or certified by MITRE, NVD, CISA, or FIRST.