Microsoft .NET Framework, SharePoint, and Visual Studio Remote Code Execution Vulnerability

Added to KEV
2021-11-03
Federal due date
2022-05-03
Vendor
Microsoft
Product
.NET Framework, SharePoint, Visual Studio
EPSS
99.8th percentile (score 0.934, as of 2026-06-08)
NVD CVSS v3.1
Ransomware use
Unknown
Upstream
https://nvd.nist.gov/vuln/detail/CVE-2020-1147

CISA short description

Microsoft .NET Framework, Microsoft SharePoint, and Visual Studio contain a remote code execution vulnerability when the software fails to check the source markup of XML file input. Successful exploitation allows an attacker to execute code in the context of the process responsible for deserialization of the XML content.

Required action

Apply updates per vendor instructions.

EPSS percentile is the FIRST.org exploit-probability ranking as of the date noted above; it moves daily. CVSS reflects NVD's analysis at time of publication.