CVE-2020-16009: Google Chromium V8 Type Confusion Vulnerability

Q: How do I fix CVE-2020-16009?

cefsharp: upgrade to 86.0.241; chrome: upgrade to 86.0.4240.183; edge: upgrade to 86.0.622.63. Exact commands for each OS are on this page.

Q: Is CVE-2020-16009 being exploited?

Yes. CVE-2020-16009 is on the CISA Known Exploited Vulnerabilities list, so treat it as patch-now.

Q: What does CVE-2020-16009 affect?

CVE-2020-16009 affects cefsharp, chrome, edge. Severity is high (CVSS 8.8). Inappropriate implementation in V8 in Google Chrome prior to 86.0.4240.183 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page.

Q: How urgent is CVE-2020-16009?

Priority 91/100. 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 8.8EXPLOITEDWATCHLISTUPGRADEUPGRADEUPGRADE

CVE-2020-16009 is a high-severity flaw (CVSS 8.8) affecting cefsharp, chrome, edge, reported as exploited in the wild. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Inappropriate implementation in V8 in Google Chrome prior to 86.0.4240.183 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page.

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	8.8 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	48.3% (top 1%)
CISA exploited list	Yes, fix due 2022-05-03
Weakness	CWE-787, CWE-843
Published	2020-11-03
Last modified	2026-06-17

Publisher (CNA): Chrome · Vendor: cefsharp · google · microsoft · opensuse

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

Am I affected?

Timeline

2020-11-03 03:15 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 02:57 UTCUpdated Record last modified

cefsharp cefsharp UPGRADE

Affected: < 86.0.241

Fixed in: 86.0.241

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy cefsharp || rpm -q cefsharp || cefsharp --version

2. UPGRADE to 86.0.241 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade cefsharp

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade cefsharp

Note

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

google chrome UPGRADE

Affected: < 86.0.4240.183

Fixed in: 86.0.4240.183

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy chrome || rpm -q chrome || chrome --version

2. UPGRADE to 86.0.4240.183 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade chrome

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade chrome

Note

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

microsoft edge UPGRADE

Affected: < 86.0.622.63

Fixed in: 86.0.622.63

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy edge || rpm -q edge || edge --version

2. UPGRADE to 86.0.622.63 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade edge

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade edge

Note

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

microsoft edge chromium UPGRADE

Affected: < 86.0.4240.183

Fixed in: 86.0.4240.183

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy edge-chromium || rpm -q edge-chromium || edge-chromium --version

2. UPGRADE to 86.0.4240.183 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade edge-chromium

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade edge-chromium

Note

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

opensuse backports sle DOWNGRADE

Affected: 15.0 sp1 · 15.0 sp2

Fixed in: no fixed release known

Safe to downgrade to: a release before 15.0

1. Check installed version

apt-cache policy backports-sle || rpm -q backports-sle || backports-sle --version

2. No fixed release: DOWNGRADE to a release before 15.0 (Debian / Ubuntu)

apt-cache madison backports-sle sudo apt install backports-sle=<VERSION_BEFORE_15.0> sudo apt-mark hold backports-sle

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

dnf --showduplicates list backports-sle sudo dnf downgrade backports-sle-<VERSION_BEFORE_15.0> sudo dnf versionlock add backports-sle

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.

opensuse leap MITIGATE

Affected: 15.1 · 15.2

Fixed in: no fixed release known

Safe to downgrade to: a release before 15.1

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Exact fixes by distribution

A distro patch exists: prefer upgrading over downgrading.

NuGet (.NET) · CefSharp.Common · FIXED · 86.0.241 · vulnerable: < 86.0.241 · source

dotnet add package CefSharp.Common --version 86.0.241

NuGet (.NET) · CefSharp.Wpf · FIXED · 86.0.241 · vulnerable: < 86.0.241 · source

dotnet add package CefSharp.Wpf --version 86.0.241

NuGet (.NET) · CefSharp.WinForms · FIXED · 86.0.241 · vulnerable: < 86.0.241 · source

dotnet add package CefSharp.WinForms --version 86.0.241

NuGet (.NET) · CefSharp.Wpf.HwndHost · FIXED · 86.0.241 · vulnerable: < 86.0.241 · source

dotnet add package CefSharp.Wpf.HwndHost --version 86.0.241

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

Debian 12 · chromium · FIXED · 87.0.4280.88-0.1

sudo apt update && sudo apt install --only-upgrade chromium dpkg --compare-versions "$(dpkg-query -W -f='${Version}' chromium)" ge "87.0.4280.88-0.1" && echo PATCHED || echo STILL-VULNERABLE

Debian 13 · chromium · FIXED · 87.0.4280.88-0.1

sudo apt update && sudo apt install --only-upgrade chromium dpkg --compare-versions "$(dpkg-query -W -f='${Version}' chromium)" ge "87.0.4280.88-0.1" && echo PATCHED || echo STILL-VULNERABLE

RHEL 6 Supplementary · chromium-browser · FIXED · chromium-browser-86.0.4240.183-1.el6_10

sudo dnf upgrade --advisory=RHSA-2020:4974 rpm -q chromium-browser

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-2020-16009?

cefsharp: upgrade to 86.0.241; chrome: upgrade to 86.0.4240.183; edge: upgrade to 86.0.622.63. Exact commands for each OS are on this page.

Is CVE-2020-16009 being exploited?

Yes. CVE-2020-16009 is on the CISA Known Exploited Vulnerabilities list, so treat it as patch-now.

What does CVE-2020-16009 affect?

CVE-2020-16009 affects cefsharp, chrome, edge. Severity is high (CVSS 8.8). Inappropriate implementation in V8 in Google Chrome prior to 86.0.4240.183 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page.

How urgent is CVE-2020-16009?

Priority 91/100. High severity; EPSS top 1%: very likely to be exploited; Exploited in the wild (CISA KEV); Public exploit reference; On your watchlist

Software pages

Microsoft Edge vulnerabilities · Google Chrome vulnerabilities · Chromium vulnerabilities

References

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