Microsoft Windows Kernel Information Disclosure Vulnerability

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

• cpe microsoft/windows 10 1809version unspecified
• cpe microsoft/windows 10 1909version unspecified
• cpe microsoft/windows 10 2004version unspecified
• cpe microsoft/windows 10 20h2version unspecified
• cpe microsoft/windows 10 21h1version unspecified
• cpe microsoft/windows server 2004version unspecified
• cpe microsoft/windows server 2019version unspecified
• cpe microsoft/windows server 20h2version unspecified
• vendor Microsoft Windowsversion unspecified

How to fix CVE-2021-31955

• Recommended remediation

  Apply updates per vendor instructions. CISA due date Nov 17, 2021.

• Official advisories

  • CISA KEV · cisa.gov
  • CVE.org · cve.org
  • FIRST EPSS · first.org
  • NIST NVD · nvd.nist.gov
  • VulnCheck KEV · vulncheck.com

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Technology hubs

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

1. Jun 8, 2021 · Catalog

   Detected

   Microsoft Windows Kernel contains an unspecified vulnerability that allows for information disclosure. Successful exploitation allows attackers to read the contents of kernel memory from a user-mode process.

2. Nov 3, 2021 · CISA KEV

   Known exploited

   Apply updates per vendor instructions.

3. Nov 17, 2021 · CISA KEV

   Remediation due

   Apply updates per vendor instructions.

4. Jun 16, 2026 · Catalog

   Updated

   Microsoft Windows Kernel contains an unspecified vulnerability that allows for information disclosure. Successful exploitation allows attackers to read the contents of kernel memory from a user-mode process.

Sources

• CISA KEVConfirmed exploitationCVE-2021-31955

  Microsoft Windows Kernel contains an unspecified vulnerability that allows for information disclosure. Successful exploitation allows attackers to read the contents of kernel memory from a user-mode process.

  cisa.gov
• CVE.orgVulnerability recordCVE-2021-31955

  Official CVE identifier

  cve.org
• FIRST EPSSExploitation probabilityCVE-2021-31955

  30-day exploitation probability 81.1%

  first.org
• NIST NVDVulnerability recordCVE-2021-31955

  Windows Kernel Information Disclosure Vulnerability

  nvd.nist.gov
• VulnCheck KEVConfirmed exploitationCVE-2021-31955

  Microsoft Windows Kernel contains an unspecified vulnerability that allows for information disclosure. Successful exploitation allows attackers to read the contents of kernel memory from a user-mode process.

  vulncheck.com

References

• VulnCheck exploitation evidence · api.msrc.microsoft.com
• VulnCheck exploitation evidence · docs.google.com
• CISA note · nvd.nist.gov
• Patch · portal.msrc.microsoft.com
• VulnCheck exploitation evidence · securelist.com
• US Government Resource · cisa.gov
• VulnCheck exploitation evidence · cisa.gov

Freshness

Last verified in this catalog Oct 17, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.