Actively exploited in the wild
Microsoft HTTP Protocol Stack Remote Code Execution Vulnerability
Microsoft - HTTP Protocol Stack · Listed in the CISA KEV since 2022-04-06. This indicates confirmed attacks in production environments.
Required action: Apply updates per vendor instructions.
CVE-2021-31166
CriticalCVSS 9.8KEVSummary
A remote code execution vulnerability exists in the HTTP Protocol Stack. Technical details are not provided in the description.
Risk Assessment
A remote attacker could execute arbitrary code in the context of the HTTP request processing service, potentially leading to full system compromise.
Recommendation
Apply available security updates for the HTTP Protocol Stack component. Limit exposure of the HTTP service to public networks to the minimum necessary.
Related vulnerabilities
- CVE-2026-87886HighActively exploited
The vulnerability is a local privilege escalation due to insecure file permissions. It affects Acronis Backup plugin for cPanel & WHM (Linux) before build 1.9.3.1021, Acronis Backup extension for Plesk (Linux) before build 1.8.11.638, and Acronis Backup plugin for DirectAdmin (Linux) before build 1.2.3.238.
- CVE-2026-87701Critical
Improper neutralization of special elements in output used by a downstream component ('injection') in Azure Cosmos DB allows an authorized attacker to elevate privileges over a network.
- CVE-2026-85889Critical
Missing authentication for a critical function in Azure AI Foundry allows an unauthorized attacker to elevate privileges over a network.
- CVE-2026-85885Critical
Improper neutralization of special elements used in a command ('command injection') in M365 Copilot allows an authorized attacker to elevate privileges over a network.
- CVE-2026-83944Critical
Improper access control in Azure Logic Apps allows an unauthorized attacker to elevate privileges over a network.
- CVE-2026-77903Critical
Authentication bypass by spoofing in Microsoft Dataverse allows an unauthorized attacker to elevate privileges over a network.
- CVE-2026-70200Critical
Improper limitation of a pathname to a restricted directory ('path traversal') in Azure Logic Apps allows an unauthorized attacker to elevate privileges over a network.
- CVE-2026-70009Critical
Improper limitation of a pathname to a restricted directory ('path traversal') in Azure Arc allows an unauthorized attacker to elevate privileges over a network.
- CVE-2026-69865Critical
Authorization bypass through a user-controlled key in Microsoft Container Registry allows an unauthorized attacker to elevate privileges over a network.
- CVE-2026-69399Critical
Elevation of Privilege vulnerability in Azure Arc. Technical details were not provided in the description.
Original NVD description (English source)
HTTP Protocol Stack Remote Code Execution Vulnerability