CVE-2026-31431: Linux Kernel Incorrect Resource Transfer Between Spheres Vulnerability

Patch now

HIGH 7.8EXPLOITEDWATCHLISTUPGRADEUPGRADEMITIGATE

CVE-2026-31431 is a high-severity flaw (CVSS 7.8) affecting linux kernel, openshift container platform, enterprise 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.

In the Linux kernel, the following vulnerability has been resolved: crypto: algif_aead - Revert to operating out-of-place This mostly reverts commit 72548b093ee3 except for the copying of the associated data. There is no benefit in operating in-place in algif_aead since the source and destination come from different mappings. Get rid of all the complexity added for in-place operation and just copy the AD directly.

Why this priority

High severity
EPSS top 1%: very likely to be exploited
Exploited in the wild (CISA KEV)
Public exploit reference
Covered by 5 security sources
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	Low
User interaction	None
EPSS exploit chance	98.1% (top 1%)
CISA exploited list	Yes, fix due 2026-05-15
Weakness	CWE-669, CWE-1288
Published	2026-04-22
Last modified	2026-09-08

Publisher (CNA): kernel.org · Vendor: linux · redhat

Last updated 2026-09-08 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-22 09:16 UTCPublished CVE record published
2026-05-01Exploited Added to the CISA Known Exploited Vulnerabilities list
2026-05-15Deadline CISA due date for US federal agencies to patch
2026-09-08 15:13 UTCUpdated Record last modified

linux linux kernel UPGRADE

Affected: >= 4.14 and < 5.10.254 · >= 5.11 and < 5.15.204 · >= 5.16 and < 6.1.170 · >= 6.2 and < 6.6.137 · >= 6.7 and < 6.12.85 · >= 6.13 and < 6.18.22 · >= 6.19 and < 6.19.12 · 7.0 rc1

Fixed in: 5.10.254, 5.15.204, 6.1.170, 6.6.137, 6.12.85, 6.18.22, 6.19.12

Safe to downgrade to: no unaffected older release

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.

redhat openshift container platform UPGRADE

Affected: >= 4.12 and < 4.12.89 · >= 4.13 and < 4.13.66 · >= 4.14 and < 4.14.65 · >= 4.15 and < 4.15.64 · >= 4.16 and < 4.16.61 · >= 4.17 and < 4.17.53 · >= 4.18 and < 4.18.40 · >= 4.19 and < 4.19.30

Fixed in: 4.12.89, 4.13.66, 4.14.65, 4.15.64, 4.16.61, 4.17.53, 4.18.40, 4.19.30, 4.20.21, 4.21.14

Safe to downgrade to: a release before 4.0

1. Check installed version

apt-cache policy openshift-container-platform || rpm -q openshift-container-platform || openshift-container-platform --version

2. UPGRADE to 4.12.89 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade openshift-container-platform

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade openshift-container-platform

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 4.0 (Debian / Ubuntu)

apt-cache madison openshift-container-platform sudo apt install openshift-container-platform=<VERSION_BEFORE_4.0> sudo apt-mark hold openshift-container-platform

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

dnf --showduplicates list openshift-container-platform sudo dnf downgrade openshift-container-platform-<VERSION_BEFORE_4.0> sudo dnf versionlock add openshift-container-platform

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.

redhat enterprise linux MITIGATE

Affected: 8.0 · 9.0 · 10.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 8.0

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.

redhat enterprise linux aus MITIGATE

Affected: 8.4 · 8.6

Fixed in: no fixed release known

Safe to downgrade to: a release before 8.4

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.

redhat enterprise linux eus MITIGATE

Affected: 8.4 · 9.4 · 9.6 · 10.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 8.4

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.

redhat enterprise linux tus MITIGATE

Affected: 8.6 · 8.8

Fixed in: no fixed release known

Safe to downgrade to: a release before 8.6

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.

Fedora 46 · python-python-ulid · FIXED · 4.1.0-2.fc46 · FEDORA-2026-3652e4825b · source

sudo dnf upgrade --advisory=FEDORA-2026-3652e4825b

Fedora ELN · gmp · FIXED · 6.3.0-7.eln159 · FEDORA-2026-1139089b36 · source

sudo dnf upgrade --advisory=FEDORA-2026-1139089b36

Ubuntu 20.04 · linux · FIXED · 5.4.0-230.250

sudo apt update && sudo apt install --only-upgrade linux dpkg --compare-versions "$(dpkg-query -W -f='${Version}' linux)" ge "5.4.0-230.250" && echo PATCHED || echo STILL-VULNERABLE

Ubuntu 22.04 · linux · FIXED · 5.15.0-179.189

sudo apt update && sudo apt install --only-upgrade linux dpkg --compare-versions "$(dpkg-query -W -f='${Version}' linux)" ge "5.15.0-179.189" && echo PATCHED || echo STILL-VULNERABLE

Ubuntu 24.04 · linux · FIXED · 6.8.0-117.117

sudo apt update && sudo apt install --only-upgrade linux dpkg --compare-versions "$(dpkg-query -W -f='${Version}' linux)" ge "6.8.0-117.117" && echo PATCHED || echo STILL-VULNERABLE

Ubuntu 25.10 · linux · FIXED · 6.17.0-29.29

sudo apt update && sudo apt install --only-upgrade linux dpkg --compare-versions "$(dpkg-query -W -f='${Version}' linux)" ge "6.17.0-29.29" && echo PATCHED || echo STILL-VULNERABLE

Ubuntu 20.04 · linux-hwe-5.15 · FIXED · 5.15.0-179.189~20.04.1

sudo apt update && sudo apt install --only-upgrade linux-hwe-5.15 dpkg --compare-versions "$(dpkg-query -W -f='${Version}' linux-hwe-5.15)" ge "5.15.0-179.189~20.04.1" && echo PATCHED || echo STILL-VULNERABLE

Debian 12 · linux · FIXED · 6.1.170-1

sudo apt update && sudo apt install --only-upgrade linux dpkg --compare-versions "$(dpkg-query -W -f='${Version}' linux)" ge "6.1.170-1" && echo PATCHED || echo STILL-VULNERABLE

Debian 13 · linux · FIXED · 6.12.85-1

sudo apt update && sudo apt install --only-upgrade linux dpkg --compare-versions "$(dpkg-query -W -f='${Version}' linux)" ge "6.12.85-1" && echo PATCHED || echo STILL-VULNERABLE

RHEL 10 · kernel · FIXED · kernel-6.12.0-124.55.1.el10_1

sudo dnf upgrade --advisory=RHSA-2026:13566 rpm -q kernel

RHEL 10.0 Extended Update Support · kernel · FIXED · kernel-6.12.0-55.71.1.el10_0

sudo dnf upgrade --advisory=RHSA-2026:13887 rpm -q kernel

RHEL 8 · kernel-rt · FIXED · kernel-rt-4.18.0-553.123.1.rt7.464.el8_10

sudo dnf upgrade --advisory=RHSA-2026:13578 rpm -q kernel-rt

RHEL 8 · kernel · FIXED · kernel-4.18.0-553.123.1.el8_10

sudo dnf upgrade --advisory=RHSA-2026:13577 rpm -q kernel

RHEL 8.4 Advanced Mission Critical Update Support · kernel · FIXED · kernel-4.18.0-305.190.1.el8_4

sudo dnf upgrade --advisory=RHSA-2026:14165 rpm -q kernel

Alpine 3.23 · docker · FIXED · docker-29.4.2-r0

apk add --upgrade docker apk info -v docker

Alpine 3.24 · docker · FIXED · docker-29.4.2-r0

apk add --upgrade docker apk info -v docker

Amazon Linux 2023 · see advisory · FIXED · ALAS2023-2026-1651 · source

sudo dnf update --advisory=ALAS2023-2026-1651

Amazon Linux 2 · see advisory · FIXED · ALAS2-2026-3289 · source

sudo yum update --advisory=ALAS2-2026-3289

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: theori-io/copy-fail-CVE-2026-31431 (4081 stars)
GitHub PoC: tgies/copy-fail-c (447 stars)
GitHub PoC: badsectorlabs/copyfail-go (360 stars)
Write-up: cert-portal.siemens.com/productcert/html/ssa-019113.html
Write-up: cert-portal.siemens.com/productcert/html/ssa-082556.html
Write-up: cert-portal.siemens.com/productcert/html/ssa-265688.html
Metasploit: Copy Fail AF_ALG + authencesn Page-Cache Write

Advisories and coverage

Official advisories

AlmaLinux Errata: [ALSA-2026:19225] Important: kernel security update 2026-05-26
IPA Japan Security Alerts: 更新：Linuxの脆弱性対策について(CVE-2026-31431、Copy Fail) 2026-05-06

Research and news

Vulners Bulletins: Linux-Kernel-Copy-Fail-CVE-2026-31431- 2026-10-27
Vulners Bulletins: CVE-2026-31431---Copy-Fail-PoC 2026-10-27
Wiz Research: Copy Fail: Universal Linux Local Privilege Escalation Vulnerability 2026-05-01
Sysdig Threat Research: CVE-2026-31431: “Copy Fail” Linux kernel flaw lets local users gain root in seconds 2026-04-30

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-2026-31431?

linux kernel: upgrade to 5.10.254, 5.15.204, 6.1.170, 6.6.137, 6.12.85, 6.18.22, 6.19.12; openshift container platform: upgrade to 4.12.89, 4.13.66, 4.14.65, 4.15.64, 4.16.61, 4.17.53, 4.18.40, 4.19.30, 4.20.21, 4.21.14; enterprise linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2026-31431 being exploited?

Yes. CVE-2026-31431 is on the CISA Known Exploited Vulnerabilities list, so treat it as patch-now.

What does CVE-2026-31431 affect?

CVE-2026-31431 affects linux kernel, openshift container platform, enterprise linux. Severity is high (CVSS 7.8). In the Linux kernel, the following vulnerability has been resolved: crypto: algif_aead - Revert to operating out-of-place This mostly reverts commit 72548b093ee3 except for the copying of the associated data. There is no benefit in opera

How urgent is CVE-2026-31431?

Priority 90/100. High severity; EPSS top 1%: very likely to be exploited; Exploited in the wild (CISA KEV); Public exploit reference; Covered by 5 security sources; On your watchlist

Software pages

Linux kernel vulnerabilities · Red Hat OpenShift vulnerabilities

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References

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