CVE-2021-31955VulnerabilityPublished 11/03/2021Updated 10/24/2026

CVE-2021-31955: Microsoft Windows Kernel Information Disclosure Vulnerability

Affects Microsoft WindowsSource CISA KEV

Severity

High

No CVSS score published yet

Exploitation: Actively exploited – in CISA KEV since 11/03/2021
KEV deadline: 11/17/2021
EPSS: 81.1% chance of exploitation in 30 days – higher than 99% of CVEs

What to do

CISA required action

Apply updates per vendor instructions.

nvd.nist.gov/vuln/detail/CVE-2021-31955 (opens in a new tab)

Description

CVE-2021-31955 is an information disclosure vulnerability in the Microsoft Windows Kernel that allows a user-mode process to read kernel memory contents. This vulnerability has been exploited in the wild. No specific affected versions or patch information are provided in the available data.

Summary

Microsoft Windows Kernel contains an unspecified vulnerability (CVE-2021-31955) that permits information disclosure by enabling attackers to read kernel memory from a user-mode process. The vulnerability has been confirmed to be exploited in the wild. No detailed technical specifics or affected version ranges are provided in the source data.

Impact

Successful exploitation of this vulnerability allows attackers to read sensitive kernel memory contents from user-mode processes, potentially exposing sensitive information. The vulnerability has been exploited in the wild, indicating active threat usage.

Mitigation

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official patch or workaround information is provided in the available data.

Weaknesses

CWE-497Unclassified weakness (opens in a new tab)

What to do

Description

AnalysisAI-generated, updated 10/24/2026, 09:20:04 UTC

Weaknesses

References

Related threats