CVE-2020-0646 Microsoft .NET Framework Remote Code Execution Vulnerability
Microsoft .NET Framework contains an improper input validation vulnerability that allows for remote code execution.
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 3 Nov 2021.
- Rated Critical severity (CVSS 9.8, scored by CISA).
- It has been in the catalogue for 1,829 days. Systems still unpatched now have almost certainly been scanned for it.
What It Is
A remote code execution vulnerability exists when the Microsoft .NET Framework fails to validate input properly, aka '.NET Framework Remote Code Execution Injection Vulnerability'.
Affected Versions
| Product | Versions |
|---|---|
| Microsoft Microsoft .NET Framework 4.6/4.6.1/4.6.2/4.7/4.7.1/4.7.2 | Windows 7 for 32-bit Systems Service Pack 1 Windows 7 for x64-based Systems Service Pack 1 Windows 8.1 for 32-bit systems Windows 8.1 for x64-based systems Windows RT 8.1 Windows Server 2008 R2 for x64-based Systems Service Pack 1 |
| Microsoft Microsoft .NET Framework 4.6.2/4.7/4.7.1/4.7.2 | Windows 10 Version 1607 for 32-bit Systems |
| Microsoft Microsoft .NET Framework 4.8 on Windows 10 Version 1803 for 32-bit Systems | unspecified |
| Microsoft Microsoft .NET Framework 4.8 on Windows 10 Version 1803 for x64-based Systems | unspecified |
| Microsoft Microsoft .NET Framework 4.8 on Windows Server, version 1803 (Server Core Installation) | unspecified |
| Microsoft Microsoft .NET Framework 4.8 on Windows 10 Version 1709 for 32-bit Systems | unspecified |
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 .NET Framework. 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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