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Home MicrosoftCVE-2021-31166

Critical

9.8CVSS

CVE-2021-31166

Vendor:Microsoft

Published: 11 May 2021

Updated 5mo ago

Generated remediation guidance and an executive summary. No account required.

Description

HTTP Protocol Stack Remote Code Execution Vulnerability

CVSS Metrics

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack Vector: network
Complexity: low
Privileges: none
User Action: none
Scope: unchanged
Confidentiality: high
Integrity: high
Availability: high
Weaknesses: CWE-416 · Use After Free CWE-416 · Use After Free

Metadata

Primary Vendor: MICROSOFT
Published: 5/11/2021
Last Modified: 10/30/2025
Source: NIST NVD
Note: Verify all details with official vendor sources before applying patches.

Affected Products

microsoft : windows_10_2004microsoft : windows_10_20h2microsoft : windows_server_2004microsoft : windows_server_20h2

Remediation Guidance

Executive Summary

View on NIST NVD

Fix CVE-2021-31166 - CRITICAL microsoft windows 10 2004 | CVEDatabase.com

Related reading

Use CWE-416, Microsoft vendor hub and Windows 10 2004 product page to widen CVE-2021-31166 into its surrounding weakness, vendor, and product context.

Compare it with CVE-2021-43226, CVE-2021-41357 and CVE-2021-40450 for nearby disclosures in the same product family. Additional editorial context is available in Weekly Security Roundup: Navigating the April 2026 Threat Landscape and Critical Framework Exploits.