CVE-2023-21808: .NET and Visual Studio Remote Code Execution Vulnerability

This month

HIGH 7.8WATCHLISTDOWNGRADEUPGRADEUPGRADE

CVE-2023-21808 is a high-severity flaw (CVSS 7.8) affecting .net, visual studio 2017, visual studio 2019. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

.NET and Visual Studio Remote Code Execution Vulnerability

Why this priority

High severity
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	1.1% (top 33%)
CISA exploited list	No
Weakness	CWE-416
Published	2023-02-14
Last modified	2026-08-19

Publisher (CNA): Microsoft Corporation · Vendor: microsoft

Last updated 2026-08-19 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2023-02-14 21:15 UTCPublished CVE record published
2026-08-19 17:18 UTCUpdated Record last modified

microsoft .net DOWNGRADE

Affected: 6.0.0 · 7.0.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 6.0.0

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 6.0.0 (Debian / Ubuntu)

apt-cache madison .net sudo apt install .net=<VERSION_BEFORE_6.0.0> sudo apt-mark hold .net

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

dnf --showduplicates list .net sudo dnf downgrade .net-<VERSION_BEFORE_6.0.0> sudo dnf versionlock add .net

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 < 15.9.51

Fixed in: 15.9.51

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 15.9.51 (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 < 16.11.24

Fixed in: 16.11.24

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 16.11.24 (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.

microsoft visual studio 2022 DOWNGRADE

Affected: 17.0 · 17.2 · 17.4

Fixed in: no fixed release known

Safe to downgrade to: a release before 17.0

1. Check installed version

apt-cache policy visual-studio-2022 || rpm -q visual-studio-2022 || visual-studio-2022 --version

2. No fixed release: DOWNGRADE to a release before 17.0 (Debian / Ubuntu)

apt-cache madison visual-studio-2022 sudo apt install visual-studio-2022=<VERSION_BEFORE_17.0> sudo apt-mark hold visual-studio-2022

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

dnf --showduplicates list visual-studio-2022 sudo dnf downgrade visual-studio-2022-<VERSION_BEFORE_17.0> sudo dnf versionlock add visual-studio-2022

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: 3.5 · 4.8 · 4.7.2 · 4.8.1 · 4.6.2 · 4.7 · 4.7.1

Fixed in: no fixed release known

Safe to downgrade to: a release before 3.5

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 3.5 (Debian / Ubuntu)

apt-cache madison .net-framework sudo apt install .net-framework=<VERSION_BEFORE_3.5> 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_3.5> 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.

Verify at the official source NVD · CVE Program · 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-2023-21808?

.net: downgrade or apply the listed mitigation; visual studio 2017: upgrade to 15.9.51; visual studio 2019: upgrade to 16.11.24. Exact commands for each OS are on this page.

Is CVE-2023-21808 being exploited?

CVE-2023-21808 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2023-21808 affect?

CVE-2023-21808 affects .net, visual studio 2017, visual studio 2019. Severity is high (CVSS 7.8). .NET and Visual Studio Remote Code Execution Vulnerability

How urgent is CVE-2023-21808?

Priority 49/100. High severity; On your watchlist

Software pages

.NET vulnerabilities · Visual Studio vulnerabilities

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References

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