CVE-2020-1147: Microsoft .NET Framework, SharePoint, and Visual Studio Remote Code Execution Vulnerability

Q: How do I fix CVE-2020-1147?

.net core: downgrade or apply the listed mitigation; .net framework: downgrade or apply the listed mitigation; sharepoint enterprise server: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Q: Is CVE-2020-1147 being exploited?

Yes. CVE-2020-1147 is on the CISA Known Exploited Vulnerabilities list, so treat it as patch-now.

Q: What does CVE-2020-1147 affect?

CVE-2020-1147 affects .net core, .net framework, sharepoint enterprise server. Severity is high (CVSS 7.8). A remote code execution vulnerability exists in .NET Framework, Microsoft SharePoint, and Visual Studio when the software fails to check the source markup of XML file input, aka '.NET Framework, SharePoint Server, and Visual Studio Remote C

Q: How urgent is CVE-2020-1147?

Priority 87/100. High severity; EPSS top 1%: very likely to be exploited; Exploited in the wild (CISA KEV); Public exploit reference; On your watchlist

Patch now

HIGH 7.8EXPLOITEDWATCHLISTDOWNGRADEDOWNGRADEDOWNGRADE

CVE-2020-1147 is a high-severity flaw (CVSS 7.8) affecting .net core, .net framework, sharepoint enterprise server, reported as exploited in the wild. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A remote code execution vulnerability exists in .NET Framework, Microsoft SharePoint, and Visual Studio when the software fails to check the source markup of XML file input, aka '.NET Framework, SharePoint Server, and Visual Studio Remote Code Execution Vulnerability'.

Why this priority

High severity
EPSS top 1%: very likely to be exploited
Exploited in the wild (CISA KEV)
Public exploit reference
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	7.8 (High)
Attack vector	Local
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	95.8% (top 1%)
CISA exploited list	Yes, fix due 2022-05-03
Published	2020-07-14
Last modified	2026-06-17

Publisher (CNA): Microsoft Corporation · Vendor: microsoft

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2020-07-14 23:15 UTCPublished CVE record published
2021-11-03Exploited Added to the CISA Known Exploited Vulnerabilities list
2022-05-03Deadline CISA due date for US federal agencies to patch
2026-06-17 03:00 UTCUpdated Record last modified

microsoft .net core DOWNGRADE

Affected: 2.1 · 3.1

Fixed in: no fixed release known

Safe to downgrade to: a release before 2.1

1. Check installed version

apt-cache policy .net-core || rpm -q .net-core || .net-core --version

2. No fixed release: DOWNGRADE to a release before 2.1 (Debian / Ubuntu)

apt-cache madison .net-core sudo apt install .net-core=<VERSION_BEFORE_2.1> sudo apt-mark hold .net-core

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list .net-core sudo dnf downgrade .net-core-<VERSION_BEFORE_2.1> sudo dnf versionlock add .net-core

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

microsoft .net framework DOWNGRADE

Affected: 2.0 sp2 · 3.0 sp2 · 3.5 · 4.6.2 · 4.7 · 4.7.1 · 4.7.2 · 4.6

Fixed in: no fixed release known

Safe to downgrade to: a release before 2.0

1. Check installed version

apt-cache policy .net-framework || rpm -q .net-framework || .net-framework --version

2. No fixed release: DOWNGRADE to a release before 2.0 (Debian / Ubuntu)

apt-cache madison .net-framework sudo apt install .net-framework=<VERSION_BEFORE_2.0> sudo apt-mark hold .net-framework

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list .net-framework sudo dnf downgrade .net-framework-<VERSION_BEFORE_2.0> sudo dnf versionlock add .net-framework

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

microsoft sharepoint enterprise server DOWNGRADE

Affected: 2013 sp1 · 2016

Fixed in: no fixed release known

Safe to downgrade to: a release before 2013

1. Check installed version

apt-cache policy sharepoint-enterprise-server || rpm -q sharepoint-enterprise-server || sharepoint-enterprise-server --version

2. No fixed release: DOWNGRADE to a release before 2013 (Debian / Ubuntu)

apt-cache madison sharepoint-enterprise-server sudo apt install sharepoint-enterprise-server=<VERSION_BEFORE_2013> sudo apt-mark hold sharepoint-enterprise-server

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list sharepoint-enterprise-server sudo dnf downgrade sharepoint-enterprise-server-<VERSION_BEFORE_2013> sudo dnf versionlock add sharepoint-enterprise-server

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

microsoft sharepoint server DOWNGRADE

Affected: 2010 sp2 · 2019

Fixed in: no fixed release known

Safe to downgrade to: a release before 2010

1. Check installed version

apt-cache policy sharepoint-server || rpm -q sharepoint-server || sharepoint-server --version

2. No fixed release: DOWNGRADE to a release before 2010 (Debian / Ubuntu)

apt-cache madison sharepoint-server sudo apt install sharepoint-server=<VERSION_BEFORE_2010> sudo apt-mark hold sharepoint-server

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list sharepoint-server sudo dnf downgrade sharepoint-server-<VERSION_BEFORE_2010> sudo dnf versionlock add sharepoint-server

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

microsoft visual studio 2017 UPGRADE

Affected: >= 15.0 and <= 15.9

Fixed in: newer than 15.9

Safe to downgrade to: a release before 15.0

1. Check installed version

apt-cache policy visual-studio-2017 || rpm -q visual-studio-2017 || visual-studio-2017 --version

2. UPGRADE to newer than 15.9 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade visual-studio-2017

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade visual-studio-2017

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 15.0 (Debian / Ubuntu)

apt-cache madison visual-studio-2017 sudo apt install visual-studio-2017=<VERSION_BEFORE_15.0> sudo apt-mark hold visual-studio-2017

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list visual-studio-2017 sudo dnf downgrade visual-studio-2017-<VERSION_BEFORE_15.0> sudo dnf versionlock add visual-studio-2017

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

microsoft visual studio 2019 UPGRADE

Affected: >= 16.0 and <= 16.6

Fixed in: newer than 16.6

Safe to downgrade to: a release before 16.0

1. Check installed version

apt-cache policy visual-studio-2019 || rpm -q visual-studio-2019 || visual-studio-2019 --version

2. UPGRADE to newer than 16.6 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade visual-studio-2019

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade visual-studio-2019

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 16.0 (Debian / Ubuntu)

apt-cache madison visual-studio-2019 sudo apt install visual-studio-2019=<VERSION_BEFORE_16.0> sudo apt-mark hold visual-studio-2019

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list visual-studio-2019 sudo dnf downgrade visual-studio-2019-<VERSION_BEFORE_16.0> sudo dnf versionlock add visual-studio-2019

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Exact fixes by distribution

A distro patch exists: prefer upgrading over downgrading.

NuGet (.NET) · Microsoft.NETCore.App · FIXED · 2.1.20 · vulnerable: >= 2.1.0, < 2.1.20 · source

dotnet add package Microsoft.NETCore.App --version 2.1.20

NuGet (.NET) · Microsoft.NETCore.App.Runtime.linux-arm · FIXED · 3.1.6 · vulnerable: >= 3.1.0, < 3.1.6 · source

dotnet add package Microsoft.NETCore.App.Runtime.linux-arm --version 3.1.6

NuGet (.NET) · Microsoft.NETCore.App.Runtime.linux-arm64 · FIXED · 3.1.6 · vulnerable: >= 3.1.0, < 3.1.6 · source

dotnet add package Microsoft.NETCore.App.Runtime.linux-arm64 --version 3.1.6

NuGet (.NET) · Microsoft.NETCore.App.Runtime.linux-musl-arm64 · FIXED · 3.1.6 · vulnerable: >= 3.1.0, < 3.1.6 · source

dotnet add package Microsoft.NETCore.App.Runtime.linux-musl-arm64 --version 3.1.6

NuGet (.NET) · Microsoft.NETCore.App.Runtime.linux-musl-x64 · FIXED · 3.1.6 · vulnerable: >= 3.1.0, < 3.1.6 · source

dotnet add package Microsoft.NETCore.App.Runtime.linux-musl-x64 --version 3.1.6

NuGet (.NET) · Microsoft.NETCore.App.Runtime.linux-x64 · FIXED · 3.1.6 · vulnerable: >= 3.1.0, < 3.1.6 · source

dotnet add package Microsoft.NETCore.App.Runtime.linux-x64 --version 3.1.6

Fedora 46 · feh · FIXED · 3.13.1-1.fc46 · FEDORA-2026-3c76a13a4f · source

sudo dnf upgrade --advisory=FEDORA-2026-3c76a13a4f

Fedora ELN · setroubleshoot · FIXED · 3.3.37-7.eln159 · FEDORA-2026-f81b122fe1 · source

sudo dnf upgrade --advisory=FEDORA-2026-f81b122fe1

RHEL 8 · dotnet · FIXED · dotnet-2.1.516-1.el8_2

sudo dnf upgrade --advisory=RHSA-2020:2938 rpm -q dotnet

RHEL 8 · dotnet3.1 · FIXED · dotnet3.1-3.1.106-1.el8_2

sudo dnf upgrade --advisory=RHSA-2020:2954 rpm -q dotnet3.1

RHEL 8.0 Update Services for SAP Solutions · dotnet · FIXED · dotnet-2.1.516-1.el8_0

sudo dnf upgrade --advisory=RHSA-2020:2989 rpm -q dotnet

RHEL 8.1 Extended Update Support · dotnet · FIXED · dotnet-2.1.516-1.el8_1

sudo dnf upgrade --advisory=RHSA-2020:2988 rpm -q dotnet

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Exploit-DB: Microsoft SharePoint Server 2019 - Remote Code Execution
Exploit-DB: Microsoft SharePoint Server 2019 - Remote Code Execution (2)
Metasploit: SharePoint DataSet / DataTable Deserialization

Verify at the official source NVD · CVE Program · CISA KEV catalog · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2020-1147?

.net core: downgrade or apply the listed mitigation; .net framework: downgrade or apply the listed mitigation; sharepoint enterprise server: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2020-1147 being exploited?

Yes. CVE-2020-1147 is on the CISA Known Exploited Vulnerabilities list, so treat it as patch-now.

What does CVE-2020-1147 affect?

CVE-2020-1147 affects .net core, .net framework, sharepoint enterprise server. Severity is high (CVSS 7.8). A remote code execution vulnerability exists in .NET Framework, Microsoft SharePoint, and Visual Studio when the software fails to check the source markup of XML file input, aka '.NET Framework, SharePoint Server, and Visual Studio Remote C

How urgent is CVE-2020-1147?

Priority 87/100. High severity; EPSS top 1%: very likely to be exploited; Exploited in the wild (CISA KEV); Public exploit reference; On your watchlist

Software pages

SharePoint vulnerabilities · .NET vulnerabilities · Visual Studio vulnerabilities

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References

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