CVE-2019-1064 Microsoft Windows AppX Deployment Service (AppXSVC) Privilege Escalation Vulnerability
A privilege escalation vulnerability exists when Windows AppXSVC improperly handles hard links. An attacker who successfully exploited this vulnerability could run processes in an elevated context.
From the CISA KEV catalogue version 2026.11.06, with Cybergen analysis. Updated 6 Nov 2026.
Should You Worry?
- CISA confirmed exploitation in the wild and added it to the Known Exploited Vulnerabilities catalogue on 15 Mar 2022.
- CISA lists it as known to be used in ransomware campaigns.
- Rated High severity (CVSS 7.8, scored by Vendor).
- It has been in the catalogue for 1,697 days. Systems still unpatched now have almost certainly been scanned for it.
What It Is
An elevation of privilege vulnerability exists when Windows AppX Deployment Service (AppXSVC) improperly handles hard links. An attacker who successfully exploited this vulnerability could run processes in an elevated context. An attacker could then install programs; view, change or delete data. To exploit this vulnerability, an attacker would first have to log on to the system. An attacker could then run a specially crafted application that could exploit the vulnerability and take control of an affected system. The security update addresses the vulnerability by correcting how Windows AppX Deployment Service handles hard links.
Affected Versions
| Product | Versions |
|---|---|
| Microsoft Windows 10 Version 1703 | 10.0.0 to before publication |
| Microsoft Windows 10 Version 1803 | 10.0.0 to before publication |
| Microsoft Windows Server, version 1803 (Server Core Installation) | 10.0.0 to before publication |
| Microsoft Windows 10 Version 1809 | 10.0.17763.0 to before publication |
| Microsoft Windows 10 Version 1809 | 10.0.0 to before publication |
| Microsoft Windows Server 2019 | 10.0.17763.0 to before publication |
From the public CVE record, as supplied by the vendor. Always confirm against the vendor advisory.
What To Do Now
- 1
Find it
Search your asset inventory and external attack surface for Microsoft Windows. Include cloud images, appliances and anything a supplier runs for you.
Attack Surface Management - 2
- 3
Hunt for compromise
If an affected system was reachable before you patched, assume it may have been hit. Check logs, new accounts, web shells and outbound connections from the date of exposure.
Incident Response - 4
Prove it is fixed
Rescan or test the system after patching. Upgrades that fail silently and forgotten secondary instances are common.
Penetration Testing
Vendor Advisories
The Compliance Clock
General guidance, not legal advice. Your obligations depend on your sector, scope and jurisdiction.
Not Sure If You Are Exposed?
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