Improper input validation in Linux kernel - CVE-2026-45840

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Main Vulnerability Database Vulnerabilities #VU132656

Improper input validation in Linux kernel - CVE-2026-45840

Published: May 28, 2026


Vulnerability identifier: #VU132656
CSH Severity: Low
CVSS v4 BT: 4.3 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]
CVE-ID: CVE-2026-45840
CWE-ID: CWE-20
Exploitation vector: Local access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to improper input validation in the openvswitch vport netlink reply helpers when handling a crafted upcall PID array in vport mutation operations. A local user can supply an oversized PID array to trigger a kernel BUG and cause a denial of service.

On systems with unprivileged user namespaces enabled, the issue is reachable via unshare -Urn.


Affected software

Linux kernel
SUSE Linux Enterprise Server 12 SP5 LTSS Extended
Debian Linux
SUSE Linux Enterprise Server 12 SP5
SUSE Linux Enterprise Server for SAP Applications 12
SUSE Linux Enterprise Server 12
SUSE Linux Enterprise High Performance Computing 12
SUSE Linux Enterprise Desktop 15
SUSE Linux Enterprise High Availability Extension 15
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise Workstation Extension 15
SUSE Linux Micro
SUSE Linux Micro Extras
SUSE Linux Enterprise Live Patching
Public Cloud Module
SUSE Real Time Module
Legacy Module
Development Tools Module
Basesystem Module
openEuler
Ubuntu
kgraft-patch-4_12_14-122_320-default
kernel-livepatch-6_4_0-150700_7_62-rt-debuginfo
kernel-livepatch-SLE15-SP7-RT_Update_17-debugsource
kernel-livepatch-6_4_0-150700_7_62-rt
kernel-livepatch-6_4_0-150700_53_63-default-debuginfo
kernel-livepatch-6_4_0-150700_53_63-default
kernel-livepatch-SLE15-SP7_Update_17-debugsource
dlm-kmp-default-debuginfo
kernel-default-devel-debuginfo
kernel-default
gfs2-kmp-default-debuginfo
cluster-md-kmp-default
kernel-syms
ocfs2-kmp-default-debuginfo
gfs2-kmp-default
ocfs2-kmp-default
kernel-default-debuginfo
dlm-kmp-default
cluster-md-kmp-default-debuginfo
kernel-default-base-debuginfo
kernel-default-debugsource
kernel-default-base
kernel-default-devel
kernel-source
kernel-macros
kernel-devel
kernel-default-man
kernel-default-kgraft
kernel-default-kgraft-devel
bpftool
python3-perf
kernel
bpftool-debuginfo
kernel-debuginfo
kernel-debugsource
kernel-tools
kernel-tools-debuginfo
kernel-tools-devel
perf
perf-debuginfo
python2-perf
python2-perf-debuginfo
python3-perf-debuginfo
kernel-headers
linux (Ubuntu package)
linux-aws (Ubuntu package)
linux-nvidia-tegra (Ubuntu package)
linux-nvidia-tegra-5.15 (Ubuntu package)
linux-ibm-5.15 (Ubuntu package)
linux-azure (Ubuntu package)
linux-azure-5.15 (Ubuntu package)
linux-azure-fips (Ubuntu package)
linux-azure-fde (Ubuntu package)
kernel-default-livepatch
kernel-kvmsmall
kernel-obs-build
kernel-64kb-devel
kernel-kvmsmall-debuginfo
kernel-kvmsmall-debugsource
kernel-64kb-debugsource
kernel-obs-build-debugsource
kernel-64kb
kernel-rt-devel-debuginfo
cluster-md-kmp-rt-debuginfo
cluster-md-kmp-rt
ocfs2-kmp-rt
gfs2-kmp-rt
dlm-kmp-rt-debuginfo
ocfs2-kmp-rt-debuginfo
kernel-rt-debuginfo
gfs2-kmp-rt-debuginfo
dlm-kmp-rt
kernel-rt
kernel-devel-rt
kernel-source-rt
kernel-rt-devel
kernel-syms-rt
kernel-rt-debugsource
kernel-zfcpdump-debugsource
reiserfs-kmp-default-debuginfo
kernel-zfcpdump-debuginfo
kernel-default-livepatch-devel
kernel-64kb-devel-debuginfo
kernel-64kb-debuginfo
kernel-default-extra
kernel-default-extra-debuginfo
kernel-docs
kernel-azure
kernel-azure-debugsource
kernel-azure-debuginfo
kernel-azure-devel
kernel-azure-devel-debuginfo
reiserfs-kmp-default
kernel-zfcpdump
linux-fips (Ubuntu package)
linux-hwe-6.8 (Ubuntu package)
linux-ibm (Ubuntu package)
linux-oracle-6.8 (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-aws-6.8 (Ubuntu package)
linux-azure-fde-6.8 (Ubuntu package)
linux-gcp-fips (Ubuntu package)
linux (Debian package)
linux-oem-7.0 (Ubuntu package)

How to mitigate CVE-2026-45840

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
kgraft-patch-4_12_14-122_320-default - update to 1-8.3.1
kernel-livepatch-6_4_0-150700_7_62-rt-debuginfo - update to 1-150700.1.3.1
kernel-livepatch-SLE15-SP7-RT_Update_17-debugsource - update to 1-150700.1.3.1
kernel-livepatch-6_4_0-150700_7_62-rt - update to 1-150700.1.3.1
kernel-livepatch-6_4_0-150700_53_63-default-debuginfo - update to 1-150700.15.3.1
kernel-livepatch-6_4_0-150700_53_63-default - update to 1-150700.15.3.1
kernel-livepatch-SLE15-SP7_Update_17-debugsource - update to 1-150700.15.3.1
dlm-kmp-default-debuginfo - addressed in versions 4.12.14-122.320.1, 6.4.0-150700.53.63.1
kernel-default-devel-debuginfo - addressed in versions 4.12.14-122.320.1, 6.4.0-48.1, 6.4.0-150700.53.63.1
kernel-default - addressed in versions 4.12.14-122.320.1, 6.4.0-48.1, 6.4.0-150700.53.63.1
gfs2-kmp-default-debuginfo - addressed in versions 4.12.14-122.320.1, 6.4.0-150700.53.63.1
cluster-md-kmp-default - addressed in versions 4.12.14-122.320.1, 6.4.0-150700.53.63.1
kernel-syms - addressed in versions 4.12.14-122.320.1, 6.4.0-48.1, 6.4.0-150700.53.63.1
ocfs2-kmp-default-debuginfo - addressed in versions 4.12.14-122.320.1, 6.4.0-150700.53.63.1
gfs2-kmp-default - addressed in versions 4.12.14-122.320.1, 6.4.0-150700.53.63.1
ocfs2-kmp-default - addressed in versions 4.12.14-122.320.1, 6.4.0-150700.53.63.1
kernel-default-debuginfo - addressed in versions 4.12.14-122.320.1, 6.4.0-48.1, 6.4.0-150700.53.63.1
dlm-kmp-default - addressed in versions 4.12.14-122.320.1, 6.4.0-150700.53.63.1
cluster-md-kmp-default-debuginfo - addressed in versions 4.12.14-122.320.1, 6.4.0-150700.53.63.1
kernel-default-base-debuginfo - update to 4.12.14-122.320.1
kernel-default-debugsource - addressed in versions 4.12.14-122.320.1, 6.4.0-48.1, 6.4.0-150700.53.63.1
kernel-default-base - addressed in versions 4.12.14-122.320.1, 6.4.0-48.1.21.25, 6.4.0-150700.53.63.1.150700.17.37.1
kernel-default-devel - addressed in versions 4.12.14-122.320.1, 6.4.0-48.1, 6.4.0-150700.53.63.1
kernel-source - addressed in versions 4.12.14-122.320.1, 6.4.0-48.1, 6.4.0-150700.53.63.1
kernel-macros - addressed in versions 4.12.14-122.320.1, 6.4.0-48.1, 6.4.0-150700.53.63.1
kernel-devel - addressed in versions 4.12.14-122.320.1, 6.4.0-48.1, 6.4.0-150700.53.63.1
kernel-default-man - update to 4.12.14-122.320.1
kernel-default-kgraft - update to 4.12.14-122.320.1
kernel-default-kgraft-devel - update to 4.12.14-122.320.1
bpftool - addressed in versions 4.19.90-2606.1.0.0375, 5.10.0-318.0.0.221
python3-perf - addressed in versions 4.19.90-2606.1.0.0375, 5.10.0-318.0.0.221
kernel - addressed in versions 4.19.90-2606.1.0.0375, 5.10.0-318.0.0.221
bpftool-debuginfo - addressed in versions 4.19.90-2606.1.0.0375, 5.10.0-318.0.0.221
kernel-debuginfo - addressed in versions 4.19.90-2606.1.0.0375, 5.10.0-318.0.0.221
kernel-debugsource - addressed in versions 4.19.90-2606.1.0.0375, 5.10.0-318.0.0.221
kernel-devel - addressed in versions 4.19.90-2606.1.0.0375, 5.10.0-318.0.0.221
kernel-source - addressed in versions 4.19.90-2606.1.0.0375, 5.10.0-318.0.0.221
kernel-tools - addressed in versions 4.19.90-2606.1.0.0375, 5.10.0-318.0.0.221
kernel-tools-debuginfo - addressed in versions 4.19.90-2606.1.0.0375, 5.10.0-318.0.0.221
kernel-tools-devel - addressed in versions 4.19.90-2606.1.0.0375, 5.10.0-318.0.0.221
perf - addressed in versions 4.19.90-2606.1.0.0375, 5.10.0-318.0.0.221
perf-debuginfo - addressed in versions 4.19.90-2606.1.0.0375, 5.10.0-318.0.0.221
python2-perf - update to 4.19.90-2606.1.0.0375
python2-perf-debuginfo - update to 4.19.90-2606.1.0.0375
python3-perf-debuginfo - addressed in versions 4.19.90-2606.1.0.0375, 5.10.0-318.0.0.221
kernel-headers - update to 5.10.0-318.0.0.221
linux (Ubuntu package) - addressed in versions 5.15.0.184.155, 5.15.0-184.194, 5.15.0-184.194~20.04.1, 5.15.0.186.166, 5.15.0-186.196, 5.15.0-186.196~20.04.1, 5.15.0.1075.78, 5.15.0-1075.79, 5.15.0.1095.94, 5.15.0-1095.103, 5.15.0.1104.100, 5.15.0-1104.109, 5.15.0.1108.107, 5.15.0-1108.114, 5.15.0.1111.115, 5.15.0-1111.120+fips1, 5.15.0.1112.102, 5.15.0.1112.109, 5.15.0-1112.122, 5.15.0-1112.122+fips1, 6.8.0-136.136, 6.8.0-1046.50, 6.8.0-1059.67, 6.8.0-1064.72, 6.8.0-1064.72~22.04.1, 6.8.1-1056.57, 6.8.1-1056.57~22.04.2, 7.0.0-28.28, 7.0.0-28.28.1, 7.0.0-1003.4, 7.0.0-1008.8
linux-aws (Ubuntu package) - addressed in versions 5.15.0.186.109, 5.15.0-186.196+fips1, 5.15.0.1106.103, 5.15.0-1106.110, 5.15.0.1107.107, 5.15.0-1107.108, 5.15.0.1112.108, 5.15.0.1112.115, 5.15.0-1112.119, 5.15.0-1112.119+fips1, 5.15.0-1112.119~20.04.1, 6.8.0-1061.64+1, 7.0.0-1009.9, 7.0.0-1015.15
linux-nvidia-tegra (Ubuntu package) - addressed in versions 5.15.0-1053.53, 5.15.0.1053.55, 5.15.0.1064.64, 5.15.0-1064.66
linux-nvidia-tegra-5.15 (Ubuntu package) - update to 5.15.0-1064.66~20.04.1
linux-ibm-5.15 (Ubuntu package) - update to 5.15.0-1106.110~20.04.1
linux-azure (Ubuntu package) - addressed in versions 5.15.0.1109.105, 5.15.0-1109.115, 5.15.0.1117.115, 5.15.0-1117.126, 6.8.0-1063.71, 6.8.0-1063.71~22.04.1, 7.0.0-1009.9, 7.0.0-1010.10
linux-azure-5.15 (Ubuntu package) - addressed in versions 5.15.0-1109.115~20.04.1, 5.15.0-1117.126~20.04.1, 5.15.0-1117.126~20.04.2
linux-azure-fips (Ubuntu package) - addressed in versions 5.15.0.1117.102, 5.15.0-1117.126+fips1, 6.8.0-1063.71+fips2
linux-azure-fde (Ubuntu package) - addressed in versions 5.15.0-1117.126, 6.8.0-1062.69
kernel-default-livepatch - addressed in versions 6.4.0-48.1, 6.4.0-150700.53.63.1
kernel-kvmsmall - update to 6.4.0-48.1
kernel-obs-build - addressed in versions 6.4.0-48.1, 6.4.0-150700.53.63.1
kernel-64kb-devel - addressed in versions 6.4.0-48.1, 6.4.0-150700.53.63.1
kernel-kvmsmall-debuginfo - update to 6.4.0-48.1
kernel-kvmsmall-debugsource - update to 6.4.0-48.1
kernel-64kb-debugsource - addressed in versions 6.4.0-48.1, 6.4.0-150700.53.63.1
kernel-obs-build-debugsource - addressed in versions 6.4.0-48.1, 6.4.0-150700.53.63.1
kernel-64kb - addressed in versions 6.4.0-48.1, 6.4.0-150700.53.63.1
kernel-rt-devel-debuginfo - update to 6.4.0-150700.7.62.1
cluster-md-kmp-rt-debuginfo - update to 6.4.0-150700.7.62.1
cluster-md-kmp-rt - update to 6.4.0-150700.7.62.1
ocfs2-kmp-rt - update to 6.4.0-150700.7.62.1
gfs2-kmp-rt - update to 6.4.0-150700.7.62.1
dlm-kmp-rt-debuginfo - update to 6.4.0-150700.7.62.1
ocfs2-kmp-rt-debuginfo - update to 6.4.0-150700.7.62.1
kernel-rt-debuginfo - update to 6.4.0-150700.7.62.1
gfs2-kmp-rt-debuginfo - update to 6.4.0-150700.7.62.1
dlm-kmp-rt - update to 6.4.0-150700.7.62.1
kernel-rt - update to 6.4.0-150700.7.62.1
kernel-devel-rt - update to 6.4.0-150700.7.62.1
kernel-source-rt - update to 6.4.0-150700.7.62.1
kernel-rt-devel - update to 6.4.0-150700.7.62.1
kernel-syms-rt - update to 6.4.0-150700.7.62.1
kernel-rt-debugsource - update to 6.4.0-150700.7.62.1
kernel-zfcpdump-debugsource - update to 6.4.0-150700.53.63.1
reiserfs-kmp-default-debuginfo - update to 6.4.0-150700.53.63.1
kernel-zfcpdump-debuginfo - update to 6.4.0-150700.53.63.1
kernel-default-livepatch-devel - update to 6.4.0-150700.53.63.1
kernel-64kb-devel-debuginfo - update to 6.4.0-150700.53.63.1
kernel-64kb-debuginfo - update to 6.4.0-150700.53.63.1
kernel-default-extra - update to 6.4.0-150700.53.63.1
kernel-default-extra-debuginfo - update to 6.4.0-150700.53.63.1
kernel-docs - update to 6.4.0-150700.53.63.1
kernel-azure - update to 6.4.0-150700.53.63.1
kernel-azure-debugsource - update to 6.4.0-150700.53.63.1
kernel-azure-debuginfo - update to 6.4.0-150700.53.63.1
kernel-azure-devel - update to 6.4.0-150700.53.63.1
kernel-azure-devel-debuginfo - update to 6.4.0-150700.53.63.1
reiserfs-kmp-default - update to 6.4.0-150700.53.63.1
kernel-zfcpdump - update to 6.4.0-150700.53.63.1
linux-fips (Ubuntu package) - addressed in versions 6.8.0-136.136+fips2, 6.8.0-136.136.2, 6.8.0-136.136.2~22.04.1, 6.8.0-1058.61
linux-hwe-6.8 (Ubuntu package) - update to 6.8.0-136.136~22.04.1
linux-ibm (Ubuntu package) - addressed in versions 6.8.0-1030.31, 6.8.0-1033.34, 6.8.0-1061.62, 6.8.0-1061.62~22.04.1, 7.0.0-1008.8, 7.0.0-1010.10
linux-oracle-6.8 (Ubuntu package) - update to 6.8.0-1058.61~22.04.1
linux-nvidia (Ubuntu package) - addressed in versions 6.8.0-1059.62, 6.8.0-1059.62.1, 6.8.0-1059.62~22.04.1
linux-aws-6.8 (Ubuntu package) - addressed in versions 6.8.0-1061.64+fips1, 6.8.0-1061.64~22.04.1
linux-azure-fde-6.8 (Ubuntu package) - update to 6.8.0-1062.69~22.04.1
linux-gcp-fips (Ubuntu package) - update to 6.8.0-1064.72+fips1
linux (Debian package) - update to 6.12.94-1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1009.9

External References

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