CVE-2023-4863: Google Chromium WebP Heap-Based Buffer Overflow Vulnerability

Patch now

HIGH 8.8EXPLOITEDWATCHLISTUPGRADEMITIGATEMITIGATE

CVE-2023-4863 is a high-severity flaw (CVSS 8.8) affecting chrome, fedora, debian linux, reported as exploited in the wild. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Heap buffer overflow in libwebp in Google Chrome prior to 116.0.5845.187 and libwebp 1.3.2 allowed a remote attacker to perform an out of bounds memory write via a crafted HTML page. (Chromium security severity: Critical)

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	100.0% (top 1%)
CISA exploited list	Yes, fix due 2023-10-04
Weakness	CWE-787
Published	2023-09-12
Last modified	2026-06-17

Publisher (CNA): Chrome · Vendor: debian · fedoraproject · google · microsoft · mozilla

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

Am I affected?

Timeline

2023-09-12 15:15 UTCPublished CVE record published
2023-09-13Exploited Added to the CISA Known Exploited Vulnerabilities list
2023-10-04Deadline CISA due date for US federal agencies to patch
2026-06-17 06:38 UTCUpdated Record last modified

google chrome UPGRADE

Affected: < 116.0.5845.187

Fixed in: 116.0.5845.187

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 116.0.5845.187 (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.

fedoraproject fedora MITIGATE

Affected: 37 · 38 · 39

Fixed in: no fixed release known

Safe to downgrade to: a release before 37

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.

debian debian linux MITIGATE

Affected: 10.0 · 11.0 · 12.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 10.0

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.

mozilla firefox UPGRADE

Affected: < 102.15.1 · < 117.0.1 · >= 115.1.0 and < 115.2.1

Fixed in: 102.15.1, 115.2.1, 117.0.1

Safe to downgrade to: a release before 115.1.0

1. Check installed version

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

2. UPGRADE to 102.15.1 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade firefox

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 115.1.0 (Debian / Ubuntu)

apt-cache madison firefox sudo apt install firefox=<VERSION_BEFORE_115.1.0> sudo apt-mark hold firefox

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

dnf --showduplicates list firefox sudo dnf downgrade firefox-<VERSION_BEFORE_115.1.0> sudo dnf versionlock add firefox

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.

mozilla thunderbird UPGRADE

Affected: < 102.15.1 · >= 115.0 and < 115.2.2

Fixed in: 102.15.1, 115.2.2

Safe to downgrade to: a release before 115.0

1. Check installed version

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

2. UPGRADE to 102.15.1 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade thunderbird

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 115.0 (Debian / Ubuntu)

apt-cache madison thunderbird sudo apt install thunderbird=<VERSION_BEFORE_115.0> sudo apt-mark hold thunderbird

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

dnf --showduplicates list thunderbird sudo dnf downgrade thunderbird-<VERSION_BEFORE_115.0> sudo dnf versionlock add thunderbird

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 edge chromium UPGRADE

Affected: < 116.0.1938.81

Fixed in: 116.0.1938.81

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 116.0.1938.81 (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.

Exact fixes by distribution

A distro patch exists: prefer upgrading over downgrading.

Rust (Cargo) · libwebp-sys2 · FIXED · 0.1.8 · vulnerable: < 0.1.8 · source

Set libwebp-sys2 >= 0.1.8 in Cargo.toml, then run: cargo update -p libwebp-sys2

Rust (Cargo) · libwebp-sys · FIXED · 0.9.3 · vulnerable: < 0.9.3 · source

Set libwebp-sys >= 0.9.3 in Cargo.toml, then run: cargo update -p libwebp-sys

npm · electron · FIXED · 22.3.24 · vulnerable: >= 22.0.0, < 22.3.24 · source

npm install electron@">=22.3.24" npm ls electron

Fedora ELN · libmamba · FIXED · 2.10.0-1.eln159 · FEDORA-2026-cc57be9e65 · source

sudo dnf upgrade --advisory=FEDORA-2026-cc57be9e65

Fedora 46 · rubygem-selenium-webdriver · FIXED · 4.34.0-5.fc46 · FEDORA-2026-111c6e6363 · source

sudo dnf upgrade --advisory=FEDORA-2026-111c6e6363

Ubuntu 22.04 · chromium-browser · NOT AFFECTED

Ubuntu 24.04 · chromium-browser · NOT AFFECTED

Ubuntu 20.04 · firefox · FIXED · 117.0.1+build2-0ubuntu0.20.04.1

sudo apt update && sudo apt install --only-upgrade firefox dpkg --compare-versions "$(dpkg-query -W -f='${Version}' firefox)" ge "117.0.1+build2-0ubuntu0.20.04.1" && echo PATCHED || echo STILL-VULNERABLE

Ubuntu 22.04 · firefox · NOT AFFECTED

Ubuntu 24.04 · firefox · NOT AFFECTED

Debian 12 · chromium · FIXED · 117.0.5938.62-1

sudo apt update && sudo apt install --only-upgrade chromium dpkg --compare-versions "$(dpkg-query -W -f='${Version}' chromium)" ge "117.0.5938.62-1" && echo PATCHED || echo STILL-VULNERABLE

Debian 13 · chromium · FIXED · 117.0.5938.62-1

sudo apt update && sudo apt install --only-upgrade chromium dpkg --compare-versions "$(dpkg-query -W -f='${Version}' chromium)" ge "117.0.5938.62-1" && echo PATCHED || echo STILL-VULNERABLE

Debian 12 · firefox-esr · FIXED · 102.15.1esr-1~deb12u1

sudo apt update && sudo apt install --only-upgrade firefox-esr dpkg --compare-versions "$(dpkg-query -W -f='${Version}' firefox-esr)" ge "102.15.1esr-1~deb12u1" && echo PATCHED || echo STILL-VULNERABLE

Debian 13 · firefox-esr · FIXED · 115.2.1esr-1

sudo apt update && sudo apt install --only-upgrade firefox-esr dpkg --compare-versions "$(dpkg-query -W -f='${Version}' firefox-esr)" ge "115.2.1esr-1" && echo PATCHED || echo STILL-VULNERABLE

RHEL 7 · thunderbird · FIXED · thunderbird-102.15.1-1.el7_9

sudo dnf upgrade --advisory=RHSA-2023:5191 rpm -q thunderbird

RHEL 7 · firefox · FIXED · firefox-102.15.1-1.el7_9

sudo dnf upgrade --advisory=RHSA-2023:5197 rpm -q firefox

RHEL 8 · firefox · FIXED · firefox-102.15.1-1.el8_8

sudo dnf upgrade --advisory=RHSA-2023:5184 rpm -q firefox

RHEL 8 · thunderbird · FIXED · thunderbird-102.15.1-1.el8_8

sudo dnf upgrade --advisory=RHSA-2023:5201 rpm -q thunderbird

RHEL 8 · libwebp · FIXED · libwebp-1.0.0-8.el8_8.1

sudo dnf upgrade --advisory=RHSA-2023:5309 rpm -q libwebp

Alpine 3.20 · libwebp · FIXED · libwebp-1.3.1-r1

apk add --upgrade libwebp apk info -v libwebp

Alpine 3.20 · chromium · FIXED · chromium-116.0.5845.187-r0

apk add --upgrade chromium apk info -v chromium

Alpine 3.20 · firefox-esr · FIXED · firefox-esr-115.2.1-r0

apk add --upgrade firefox-esr apk info -v firefox-esr

Alpine 3.20 · qt5-qtimageformats · FIXED · qt5-qtimageformats-5.15.10_git20230612-r1

apk add --upgrade qt5-qtimageformats apk info -v qt5-qtimageformats

Amazon Linux 2023 · see advisory · FIXED · ALAS2023-2023-355 · source

sudo dnf update --advisory=ALAS2023-2023-355

Public exploits and detection

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

GitHub PoC: mistymntncop/CVE-2023-4863 (320 stars)
GitHub PoC: LiveOverflow/webp-CVE-2023-4863 (56 stars)
GitHub PoC: caoweiquan322/NotEnough (25 stars)
Write-up: blog.isosceles.com/the-webp-0day/
Write-up: bugzilla.suse.com/show_bug.cgi?id=1215231
Write-up: github.com/webmproject/libwebp/commit/902bc9190331343b2017211debcec8d2ab87e17a
GitHub PoC: CrackerCat/CVE-2023-4863-

Advisories and coverage

Official advisories

CISA Alerts and Advisories: Mitsubishi Electric and Mitsubishi Electric Iconics Digital Solutions GENESIS, GENESIS64, ICONICS Suite, Hyper Historian, AnalytiX, MobileHM 2026-10-27

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-2023-4863?

chrome: upgrade to 116.0.5845.187; fedora: mitigate or apply the listed mitigation; debian linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2023-4863 being exploited?

Yes. CVE-2023-4863 is on the CISA Known Exploited Vulnerabilities list, so treat it as patch-now.

What does CVE-2023-4863 affect?

CVE-2023-4863 affects chrome, fedora, debian linux. Severity is high (CVSS 8.8). Heap buffer overflow in libwebp in Google Chrome prior to 116.0.5845.187 and libwebp 1.3.2 allowed a remote attacker to perform an out of bounds memory write via a crafted HTML page. (Chromium security severity: Critical)

How urgent is CVE-2023-4863?

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 · Debian vulnerabilities · Google Chrome vulnerabilities · Mozilla Firefox vulnerabilities · Chromium vulnerabilities · Mozilla Thunderbird vulnerabilities

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References

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