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CVE-2021-43890: Microsoft Windows AppX Installer Spoofing Vulnerability
Microsoft Windows · in CISA KEV since 2021-12-15
2021-12-15added to KEV
2021-12-29federal remediation due date
10.29%EPSS exploit probability (30 days) 95.5th percentile
7.1 HIGHCVSS 3.1
Knownknown ransomware use
0days from NVD publication to KEV
What it is
Microsoft Windows AppX Installer contains a spoofing vulnerability which has a high impacts to confidentiality, integrity, and availability.
Required action (CISA)
Apply updates per vendor instructions.
| CWE | — |
|---|---|
| CVSS vector | CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H |
| NVD published | 2021-12-15 (Analyzed) |
Original records: NVD · CISA KEV · JSON: /api/cve/CVE-2021-43890.json · all KEV CVEs
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Get the full file: Exploited Vulnerabilities Brief – September 2026 ($29): this month's KEV additions ranked by EPSS, ransomware use and due date, ready to hand to a patch team. Checkout by Polar.