Improper input validation in Linux kernel - CVE-2026-43265

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Main Vulnerability Database Vulnerabilities #VU130442

Improper input validation in Linux kernel - CVE-2026-43265

Published: May 7, 2026


Vulnerability identifier: #VU130442
CSH Severity: Medium
CVSS v4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-43265
CWE-ID: CWE-20
Exploitation vector: Remote access
Exploit availability: No public exploit available

Vulnerability details

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

The vulnerability exists due to improper state validation in KVM x86 nested virtualization handling when processing userspace-supplied MP_STATE or injected events for a blocked vCPU while L2 is active. A remote user can place the vCPU into an invalid state to cause a denial of service.

The issue can result in a spurious userspace exit, typically with KVM_EXIT_UNKNOWN, after exiting a blocking state.


Affected software

Linux kernel
SUSE Linux Enterprise Workstation Extension 15
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise High Availability Extension 15
SUSE Linux Enterprise Desktop 15
Development Tools Module
SUSE Linux Enterprise Live Patching
Public Cloud Module
Legacy Module
Basesystem Module
SUSE Real Time Module
Ubuntu
openEuler
kernel-livepatch-6_4_0-150700_7_54-rt-debuginfo
kernel-livepatch-SLE15-SP7-RT_Update_15-debugsource
kernel-livepatch-6_4_0-150700_7_54-rt
kernel-livepatch-6_4_0-150700_53_55-default
kernel-livepatch-6_4_0-150700_53_55-default-debuginfo
kernel-livepatch-SLE15-SP7_Update_15-debugsource
gfs2-kmp-rt
kernel-syms-rt
ocfs2-kmp-rt
cluster-md-kmp-rt
gfs2-kmp-rt-debuginfo
kernel-devel-rt
kernel-source-rt
kernel-rt
kernel-rt-debugsource
cluster-md-kmp-rt-debuginfo
kernel-rt-debuginfo
kernel-rt-devel-debuginfo
dlm-kmp-rt-debuginfo
kernel-rt-devel
ocfs2-kmp-rt-debuginfo
dlm-kmp-rt
kernel-64kb
kernel-64kb-devel-debuginfo
cluster-md-kmp-default
kernel-default-debuginfo
ocfs2-kmp-default-debuginfo
dlm-kmp-default-debuginfo
kernel-default-debugsource
gfs2-kmp-default
gfs2-kmp-default-debuginfo
dlm-kmp-default
cluster-md-kmp-default-debuginfo
ocfs2-kmp-default
kernel-default
kernel-obs-build
kernel-syms
kernel-docs
kernel-zfcpdump-debugsource
kernel-zfcpdump-debuginfo
kernel-zfcpdump
kernel-macros
kernel-devel
kernel-default-devel
kernel-default-devel-debuginfo
kernel-64kb-debuginfo
kernel-64kb-devel
kernel-64kb-debugsource
kernel-obs-build-debugsource
kernel-source
reiserfs-kmp-default-debuginfo
reiserfs-kmp-default
kernel-azure
kernel-azure-debugsource
kernel-azure-debuginfo
kernel-azure-devel-debuginfo
kernel-azure-devel
kernel-default-extra-debuginfo
kernel-default-extra
kernel-default-livepatch
kernel-default-livepatch-devel
kernel-default-base
kernel
bpftool
bpftool-debuginfo
kernel-debuginfo
python3-perf-debuginfo
python3-perf
perf-debuginfo
perf
kernel-tools-devel
kernel-tools-debuginfo
kernel-tools
kernel-headers
kernel-debugsource
kernel-extra-modules
linux (Ubuntu package)
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-aws (Ubuntu package)
linux-azure-fde (Ubuntu package)
linux-azure-fde-6.8 (Ubuntu package)
linux-azure (Ubuntu package)
linux-azure-fips (Ubuntu package)
linux-gcp-fips (Ubuntu package)

How to mitigate CVE-2026-43265

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
kernel-livepatch-6_4_0-150700_7_54-rt-debuginfo - update to 1-150700.1.3.1
kernel-livepatch-SLE15-SP7-RT_Update_15-debugsource - update to 1-150700.1.3.1
kernel-livepatch-6_4_0-150700_7_54-rt - update to 1-150700.1.3.1
kernel-livepatch-6_4_0-150700_53_55-default - update to 1-150700.15.3.1
kernel-livepatch-6_4_0-150700_53_55-default-debuginfo - update to 1-150700.15.3.1
kernel-livepatch-SLE15-SP7_Update_15-debugsource - update to 1-150700.15.3.1
gfs2-kmp-rt - update to 6.4.0-150700.7.54.1
kernel-syms-rt - update to 6.4.0-150700.7.54.1
ocfs2-kmp-rt - update to 6.4.0-150700.7.54.1
cluster-md-kmp-rt - update to 6.4.0-150700.7.54.1
gfs2-kmp-rt-debuginfo - update to 6.4.0-150700.7.54.1
kernel-devel-rt - update to 6.4.0-150700.7.54.1
kernel-source-rt - update to 6.4.0-150700.7.54.1
kernel-rt - update to 6.4.0-150700.7.54.1
kernel-rt-debugsource - update to 6.4.0-150700.7.54.1
cluster-md-kmp-rt-debuginfo - update to 6.4.0-150700.7.54.1
kernel-rt-debuginfo - update to 6.4.0-150700.7.54.1
kernel-rt-devel-debuginfo - update to 6.4.0-150700.7.54.1
dlm-kmp-rt-debuginfo - update to 6.4.0-150700.7.54.1
kernel-rt-devel - update to 6.4.0-150700.7.54.1
ocfs2-kmp-rt-debuginfo - update to 6.4.0-150700.7.54.1
dlm-kmp-rt - update to 6.4.0-150700.7.54.1
kernel-64kb - update to 6.4.0-150700.53.55.1
kernel-64kb-devel-debuginfo - update to 6.4.0-150700.53.55.1
cluster-md-kmp-default - update to 6.4.0-150700.53.55.1
kernel-default-debuginfo - update to 6.4.0-150700.53.55.1
ocfs2-kmp-default-debuginfo - update to 6.4.0-150700.53.55.1
dlm-kmp-default-debuginfo - update to 6.4.0-150700.53.55.1
kernel-default-debugsource - update to 6.4.0-150700.53.55.1
gfs2-kmp-default - update to 6.4.0-150700.53.55.1
gfs2-kmp-default-debuginfo - update to 6.4.0-150700.53.55.1
dlm-kmp-default - update to 6.4.0-150700.53.55.1
cluster-md-kmp-default-debuginfo - update to 6.4.0-150700.53.55.1
ocfs2-kmp-default - update to 6.4.0-150700.53.55.1
kernel-default - update to 6.4.0-150700.53.55.1
kernel-obs-build - update to 6.4.0-150700.53.55.1
kernel-syms - update to 6.4.0-150700.53.55.1
kernel-docs - update to 6.4.0-150700.53.55.1
kernel-zfcpdump-debugsource - update to 6.4.0-150700.53.55.1
kernel-zfcpdump-debuginfo - update to 6.4.0-150700.53.55.1
kernel-zfcpdump - update to 6.4.0-150700.53.55.1
kernel-macros - update to 6.4.0-150700.53.55.1
kernel-devel - update to 6.4.0-150700.53.55.1
kernel-default-devel - update to 6.4.0-150700.53.55.1
kernel-default-devel-debuginfo - update to 6.4.0-150700.53.55.1
kernel-64kb-debuginfo - update to 6.4.0-150700.53.55.1
kernel-64kb-devel - update to 6.4.0-150700.53.55.1
kernel-64kb-debugsource - update to 6.4.0-150700.53.55.1
kernel-obs-build-debugsource - update to 6.4.0-150700.53.55.1
kernel-source - update to 6.4.0-150700.53.55.1
reiserfs-kmp-default-debuginfo - update to 6.4.0-150700.53.55.1
reiserfs-kmp-default - update to 6.4.0-150700.53.55.1
kernel-azure - update to 6.4.0-150700.53.55.1
kernel-azure-debugsource - update to 6.4.0-150700.53.55.1
kernel-azure-debuginfo - update to 6.4.0-150700.53.55.1
kernel-azure-devel-debuginfo - update to 6.4.0-150700.53.55.1
kernel-azure-devel - update to 6.4.0-150700.53.55.1
kernel-default-extra-debuginfo - update to 6.4.0-150700.53.55.1
kernel-default-extra - update to 6.4.0-150700.53.55.1
kernel-default-livepatch - update to 6.4.0-150700.53.55.1
kernel-default-livepatch-devel - update to 6.4.0-150700.53.55.1
kernel-default-base - update to 6.4.0-150700.53.55.1.150700.17.33.1
kernel-devel - addressed in versions 6.6.0-145.0.10.137, 6.6.0-145.0.10.141, 6.6.0-145.0.10.149
kernel - addressed in versions 6.6.0-145.0.10.137, 6.6.0-145.0.10.141, 6.6.0-145.0.10.149
bpftool - addressed in versions 6.6.0-145.0.10.137, 6.6.0-145.0.10.141, 6.6.0-145.0.10.149
bpftool-debuginfo - addressed in versions 6.6.0-145.0.10.137, 6.6.0-145.0.10.141, 6.6.0-145.0.10.149
kernel-debuginfo - addressed in versions 6.6.0-145.0.10.137, 6.6.0-145.0.10.141, 6.6.0-145.0.10.149
python3-perf-debuginfo - addressed in versions 6.6.0-145.0.10.137, 6.6.0-145.0.10.141, 6.6.0-145.0.10.149
python3-perf - addressed in versions 6.6.0-145.0.10.137, 6.6.0-145.0.10.141, 6.6.0-145.0.10.149
perf-debuginfo - addressed in versions 6.6.0-145.0.10.137, 6.6.0-145.0.10.141, 6.6.0-145.0.10.149
perf - addressed in versions 6.6.0-145.0.10.137, 6.6.0-145.0.10.141, 6.6.0-145.0.10.149
kernel-tools-devel - addressed in versions 6.6.0-145.0.10.137, 6.6.0-145.0.10.141, 6.6.0-145.0.10.149
kernel-tools-debuginfo - addressed in versions 6.6.0-145.0.10.137, 6.6.0-145.0.10.141, 6.6.0-145.0.10.149
kernel-tools - addressed in versions 6.6.0-145.0.10.137, 6.6.0-145.0.10.141, 6.6.0-145.0.10.149
kernel-source - addressed in versions 6.6.0-145.0.10.137, 6.6.0-145.0.10.141, 6.6.0-145.0.10.149
kernel-headers - addressed in versions 6.6.0-145.0.10.137, 6.6.0-145.0.10.141, 6.6.0-145.0.10.149
kernel-debugsource - addressed in versions 6.6.0-145.0.10.137, 6.6.0-145.0.10.141, 6.6.0-145.0.10.149
kernel-extra-modules - update to 6.6.0-145.0.10.141
linux (Ubuntu package) - addressed in versions 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
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
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-aws (Ubuntu package) - update to 6.8.0-1061.64+1
linux-azure-fde (Ubuntu package) - update to 6.8.0-1062.69
linux-azure-fde-6.8 (Ubuntu package) - update to 6.8.0-1062.69~22.04.1
linux-azure (Ubuntu package) - addressed in versions 6.8.0-1063.71, 6.8.0-1063.71~22.04.1
linux-azure-fips (Ubuntu package) - update to 6.8.0-1063.71+fips2
linux-gcp-fips (Ubuntu package) - update to 6.8.0-1064.72+fips1

External References

Related Security Bulletins