Microsoft Windows AppX Installer Spoofing Vulnerability (CVE-2021-43890) | HOL Guard CVE

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CVE 2021 43890 microsoft windows appx installer spoofing vulnerability

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CVE 2021 43890 microsoft windows appx installer spoofing vulnerability

HOL Guard

Public security guidance for teams protecting AI harnesses, MCP servers, skills, prompts, and local tool execution.

AI Security

Prompt injection
MCP security
Supply chain

Resources

Trust packet
Harness setup
Redacted warnings
Safe labs

Product

Install Guard
Pricing
Open dashboard

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HOL

Install Pricing Enterprise Affiliates Docs Open App

Docs

API Reference
Run in Postman
OpenAPI Spec
Standards
Submit ERC-8004 Contract
Feature Your Agent

Best Agents

Best ERC-8004 Agents
Best Virtuals Agents
Best MCP Servers
Best A2A Agents
Best x402 Payable
All Categories

Community

Telegram
X

More

Blog
GitHub
Privacy Policy
Terms of Service

Settings

Copyright © 2026 HOL DAO LLC. All rights reserved.

Microsoft Windows AppX Installer Spoofing Vulnerability (CVE-2021-43890) | HOL Guard CVE