PatchTheCVECVE-2022-37434: zlib through 1.2.12 has a heap-based buffer over-read or buffer overflow in inflate in inflate.c via a large g
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CRITICAL 9.8REMOTEWATCHLISTUPGRADEMITIGATEMITIGATE
CVE-2022-37434 is a critical-severity flaw (CVSS 9.8) affecting zlib, fedora, debian linux. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
zlib through 1.2.12 has a heap-based buffer over-read or buffer overflow in inflate in inflate.c via a large gzip header extra field. NOTE: only applications that call inflateGetHeader are affected. Some common applications bundle the affected zlib source code but may be unable to call inflateGetHeader (e.g., see the nodejs/node reference).
Why this priority
- Critical severity
- EPSS top 3%: very likely to be exploited
- Public exploit reference
- Remotely exploitable, no login, no user action
- On your watchlist
A fixed release or distro patch exists.
Last updated 2026-10-14 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
zlib zlib UPGRADE
Affected: <= 1.2.12
Fixed in: newer than 1.2.12
Safe to downgrade to: no unaffected older release
1. Check installed version
apt-cache policy zlib || rpm -q zlib || zlib --version
2. UPGRADE to newer than 1.2.12 (Debian / Ubuntu)
sudo apt update && sudo apt install --only-upgrade zlib
2. UPGRADE (RHEL / Amazon Linux / Fedora)
sudo dnf upgrade zlib
Note
Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.
fedoraproject fedora MITIGATE
Affected: 35 · 36 · 37
Fixed in: no fixed release known
Safe to downgrade to: a release before 35
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
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.
netapp active iq unified manager MITIGATE
Affected: all versions
Fixed in: no fixed release known
Safe to downgrade to: no unaffected older release
1. Check installed version
apt-cache policy active-iq-unified-manager || rpm -q active-iq-unified-manager || active-iq-unified-manager --version
No fixed or unaffected release known
Apply the vendor mitigation from the advisory, disable the affected feature, or restrict network access.
netapp active iq unified manager MITIGATE
Affected: all versions
Fixed in: no fixed release known
Safe to downgrade to: no unaffected older release
1. Check installed version
apt-cache policy active-iq-unified-manager || rpm -q active-iq-unified-manager || active-iq-unified-manager --version
No fixed or unaffected release known
Apply the vendor mitigation from the advisory, disable the affected feature, or restrict network access.
netapp hci MITIGATE
Affected: all versions
Fixed in: no fixed release known
Safe to downgrade to: no unaffected older release
1. Check installed version
apt-cache policy hci || rpm -q hci || hci --version
No fixed or unaffected release known
Apply the vendor mitigation from the advisory, disable the affected feature, or restrict network access.
Exact fixes by distribution
A distro patch exists: prefer upgrading over downgrading.
Fedora ELN · luksmeta · FIXED · 11-3.eln159 · FEDORA-2026-5176083b78 · source
sudo dnf upgrade --advisory=FEDORA-2026-5176083b78
Fedora 46 · openscad · FIXED · 2021.01-34.fc46 · FEDORA-2026-faf1721128 · source
sudo dnf upgrade --advisory=FEDORA-2026-faf1721128
Ubuntu 20.04 · klibc · FIXED · 2.0.7-1ubuntu5.2
sudo apt update && sudo apt install --only-upgrade klibc
dpkg --compare-versions "$(dpkg-query -W -f='${Version}' klibc)" ge "2.0.7-1ubuntu5.2" && echo PATCHED || echo STILL-VULNERABLE
Ubuntu 22.04 · klibc · FIXED · 2.0.10-4ubuntu0.1
sudo apt update && sudo apt install --only-upgrade klibc
dpkg --compare-versions "$(dpkg-query -W -f='${Version}' klibc)" ge "2.0.10-4ubuntu0.1" && echo PATCHED || echo STILL-VULNERABLE
Ubuntu 24.04 · klibc · FIXED · 2.0.13-4ubuntu0.1
sudo apt update && sudo apt install --only-upgrade klibc
dpkg --compare-versions "$(dpkg-query -W -f='${Version}' klibc)" ge "2.0.13-4ubuntu0.1" && echo PATCHED || echo STILL-VULNERABLE
Ubuntu 22.04 · rsync · NOT AFFECTED
Ubuntu 20.04 · rsync · FIXED · 3.1.3-8ubuntu0.4
sudo apt update && sudo apt install --only-upgrade rsync
dpkg --compare-versions "$(dpkg-query -W -f='${Version}' rsync)" ge "3.1.3-8ubuntu0.4" && echo PATCHED || echo STILL-VULNERABLE
Debian 12 · libz-mingw-w64 · FIXED · 1.2.12+dfsg-2
sudo apt update && sudo apt install --only-upgrade libz-mingw-w64
dpkg --compare-versions "$(dpkg-query -W -f='${Version}' libz-mingw-w64)" ge "1.2.12+dfsg-2" && echo PATCHED || echo STILL-VULNERABLE
Debian 13 · libz-mingw-w64 · FIXED · 1.2.12+dfsg-2
sudo apt update && sudo apt install --only-upgrade libz-mingw-w64
dpkg --compare-versions "$(dpkg-query -W -f='${Version}' libz-mingw-w64)" ge "1.2.12+dfsg-2" && echo PATCHED || echo STILL-VULNERABLE
Debian 12 · zlib · FIXED · 1:1.2.11.dfsg-4.1
sudo apt update && sudo apt install --only-upgrade zlib
dpkg --compare-versions "$(dpkg-query -W -f='${Version}' zlib)" ge "1:1.2.11.dfsg-4.1" && echo PATCHED || echo STILL-VULNERABLE
Debian 13 · zlib · FIXED · 1:1.2.11.dfsg-4.1
sudo apt update && sudo apt install --only-upgrade zlib
dpkg --compare-versions "$(dpkg-query -W -f='${Version}' zlib)" ge "1:1.2.11.dfsg-4.1" && echo PATCHED || echo STILL-VULNERABLE
RHEL 7 · zlib · FIXED · zlib-1.2.7-21.el7_9
sudo dnf upgrade --advisory=RHSA-2023:1095
rpm -q zlib
RHEL 8 · zlib · FIXED · zlib-1.2.11-19.el8_6
sudo dnf upgrade --advisory=RHSA-2022:7106
rpm -q zlib
RHEL 8 · rsync · FIXED · rsync-3.1.3-19.el8
sudo dnf upgrade --advisory=RHSA-2022:7793
rpm -q rsync
RHEL 8.6 Extended Update Support · rsync · FIXED · rsync-3.1.3-14.el8_6.5
sudo dnf upgrade --advisory=RHSA-2024:0254
rpm -q rsync
RHEL 9 · zlib · FIXED · zlib-1.2.11-32.el9_0
sudo dnf upgrade --advisory=RHSA-2022:7314
rpm -q zlib
Alpine 3.20 · zlib · FIXED · zlib-1.2.12-r2
apk add --upgrade zlib
apk info -v zlib
Alpine 3.20 · zlib-ng · FIXED · zlib-ng-2.0.6-r0
apk add --upgrade zlib-ng
apk info -v zlib-ng
Alpine 3.21 · zlib · FIXED · zlib-1.2.12-r2
apk add --upgrade zlib
apk info -v zlib
Alpine 3.21 · zlib-ng · FIXED · zlib-ng-2.0.6-r0
apk add --upgrade zlib-ng
apk info -v zlib-ng
sudo dnf update --advisory=ALAS2023-2023-003
sudo yum update --advisory=ALAS2-2023-2074
sudo yum update --advisory=ALAS-2022-1650
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: xen0bit/CVE-2022-37434_poc (3 stars)
- GitHub PoC: Trinadh465/external_zlib_CVE-2022-37434 (0 stars)
- Write-up: github.com/ivd38/zlib_overflow
- GitHub PoC: nidhi7598/external_zlib-1.2.11_AOSP_10_r33_CVE-2022-37434
Advisories and coverage
Official advisories
- zlib Releases: zlib 1.2.13 2022-10-14
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.
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-2022-37434?
zlib: upgrade to newer than 1.2.12; 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-2022-37434 being exploited?
CVE-2022-37434 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-2022-37434 affect?
CVE-2022-37434 affects zlib, fedora, debian linux. Severity is critical (CVSS 9.8). zlib through 1.2.12 has a heap-based buffer over-read or buffer overflow in inflate in inflate.c via a large gzip header extra field. NOTE: only applications that call inflateGetHeader are affected. Some common applications bundle the affec
How urgent is CVE-2022-37434?
Priority 74/100. Critical severity; EPSS top 3%: very likely to be exploited; Public exploit reference; Remotely exploitable, no login, no user action; On your watchlist
Software pages
Node.js vulnerabilities · Debian vulnerabilities · zlib vulnerabilities
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