Use-after-free in Linux kernel - CVE-2026-31414

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Main Vulnerability Database Vulnerabilities #VU125863

Use-after-free in Linux kernel - CVE-2026-31414

Published: April 14, 2026


Vulnerability identifier: #VU125863
CSH Severity: Low
CVSS v4: 6.8 [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]
CVE-ID: CVE-2026-31414
CWE-ID: CWE-416
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 a use-after-free in nf_conntrack_expect when dumping the helper name via ctnetlink or /proc. A local user can trigger access to freed conntrack helper state to cause a denial of service.

The issue involves unsafe use of nfct_help() without holding a reference to the master conntrack.


Affected software

Linux kernel
Debian Linux
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Workstation Extension 15
SUSE Linux Enterprise High Availability Extension 15
SUSE Linux Enterprise Desktop 15
SUSE Linux Micro
SUSE Linux Micro Extras
Ubuntu
SUSE Real Time Module
Development Tools Module
SUSE Linux Enterprise Live Patching
Public Cloud Module
Legacy Module
Basesystem Module
openEuler
linux (Ubuntu package)
linux-lts-xenial (Ubuntu package)
linux-kvm (Ubuntu package)
linux-aws (Ubuntu package)
linux-fips (Ubuntu package)
linux-hwe-6.17 (Ubuntu package)
linux-gcp-6.17 (Ubuntu package)
linux-oracle-6.17 (Ubuntu package)
linux-azure-6.17 (Ubuntu package)
linux-oem-6.17 (Ubuntu package)
linux-nvidia-6.17 (Ubuntu package)
linux-realtime-6.17 (Ubuntu package)
kernel-livepatch-6_4_0-150700_7_62-rt
kernel-livepatch-SLE15-SP7-RT_Update_17-debugsource
kernel-livepatch-6_4_0-150700_7_62-rt-debuginfo
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
kernel-devel
perf
perf-debuginfo
python3-perf
python3-perf-debuginfo
kernel-tools-devel
kernel-tools-debuginfo
kernel-tools
kernel-source
kernel-headers
kernel-debugsource
kernel-debuginfo
bpftool-debuginfo
bpftool
kernel
kernel-kvmsmall-debugsource
kernel-kvmsmall-debuginfo
kernel-default-livepatch
kernel-kvmsmall
kernel-macros
kernel-default
kernel-64kb
kernel-syms
kernel-default-devel
kernel-default-debugsource
kernel-obs-build-debugsource
kernel-obs-build
kernel-64kb-debugsource
kernel-64kb-devel
kernel-default-devel-debuginfo
kernel-default-debuginfo
kernel-default-base
ocfs2-kmp-rt-debuginfo
cluster-md-kmp-rt
kernel-rt-debugsource
kernel-syms-rt
kernel-rt-devel
cluster-md-kmp-rt-debuginfo
kernel-rt-devel-debuginfo
ocfs2-kmp-rt
gfs2-kmp-rt
dlm-kmp-rt-debuginfo
kernel-rt-debuginfo
gfs2-kmp-rt-debuginfo
dlm-kmp-rt
kernel-rt
kernel-devel-rt
kernel-source-rt
gfs2-kmp-default-debuginfo
kernel-zfcpdump-debugsource
kernel-default-extra
kernel-default-livepatch-devel
cluster-md-kmp-default
dlm-kmp-default
ocfs2-kmp-default
cluster-md-kmp-default-debuginfo
gfs2-kmp-default
ocfs2-kmp-default-debuginfo
dlm-kmp-default-debuginfo
kernel-azure-devel
kernel-default-extra-debuginfo
kernel-docs
kernel-azure
kernel-azure-debugsource
kernel-azure-debuginfo
kernel-zfcpdump-debuginfo
kernel-azure-devel-debuginfo
reiserfs-kmp-default-debuginfo
reiserfs-kmp-default
kernel-zfcpdump
kernel-64kb-devel-debuginfo
kernel-64kb-debuginfo
kernel-extra-modules
linux-aws-hwe (Ubuntu package)
linux-oracle (Ubuntu package)
linux-azure (Ubuntu package)
linux-oracle-5.4 (Ubuntu package)
linux-aws-fips (Ubuntu package)
linux-gcp-fips (Ubuntu package)
linux-azure-5.4 (Ubuntu package)
linux-azure-5.15 (Ubuntu package)
linux-lowlatency (Ubuntu package)
linux-nvidia-tegra-igx (Ubuntu package)
linux-raspi (Ubuntu package)
linux-aws-5.15 (Ubuntu package)
linux-azure-fde-5.15 (Ubuntu package)
linux (Debian 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-azure-fde (Ubuntu package)
linux-azure-fips (Ubuntu package)

How to mitigate CVE-2026-31414

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux (Ubuntu package) - addressed in versions 3.13.0-215.266, 4.4.0-284.318, 4.15.0-254.266, 4.15.0-1150.162, 4.15.0-1177.182, 4.15.0-1188.205, 4.15.0-1195.208, 4.15.0-1205.220, 4.15.0-2096.102, 4.15.0-2113.119, 4.15.0-2133.139, 4.15.0.254.238, 4.15.0.1150.147, 4.15.0.1177.168, 4.15.0.1188.201~16.04.1, 4.15.0.1195.193, 4.15.0.1205.173, 4.15.0.2096.94, 4.15.0.2113.109, 4.15.0.2133.127, 5.4.0-234.254~18.04.1, 5.4.0-234.254, 5.4.0-1066.69, 5.4.0-1080.84, 5.4.0-1108.113~18.04.1, 5.4.0-1108.113, 5.4.0-1121.128, 5.4.0-1136.146, 5.4.0-1145.158~18.04.1, 5.4.0-1145.158, 5.4.0-1160.170+fips1, 5.4.0-1162.173~18.04.1, 5.4.0-1162.173, 5.4.0-1165.174~18.04.1, 5.4.0-1165.174, 5.4.0-1167.173, 5.4.0.234.226, 5.4.0.1080.80, 5.4.0.1108.137, 5.4.0.1121.117, 5.4.0.1136.133, 5.4.0.1145.176, 5.4.0.1160.154, 5.4.0.1162.160, 5.4.0.1165.167, 5.4.0.1167.159, 5.15.0-187.197, 5.15.0-1065.67~20.04.1, 5.15.0-1065.67, 5.15.0-1076.80, 5.15.0-1096.104, 5.15.0-1105.107, 5.15.0-1105.110, 5.15.0-1107.111~20.04.1, 5.15.0-1108.109, 5.15.0-1108.114~20.04.1, 5.15.0-1108.114, 5.15.0-1110.116~20.04.1, 5.15.0-1112.121, 5.15.0-1113.120, 5.15.0-1113.120+fips1, 5.15.0-1118.127, 5.15.0-1118.127+fips1, 5.15.0.187.167, 5.15.0.1065.65, 5.15.0.1076.79~20.04.1, 5.15.0.1096.95, 5.15.0.1105.101, 5.15.0.1105.109, 5.15.0.1107.104, 5.15.0.1107.111, 5.15.0.1108.107, 5.15.0.1108.108, 5.15.0.1112.116, 5.15.0.1113.109, 5.15.0.1113.116, 5.15.0.1118.103, 5.15.0.1118.116, 6.8.0-136.136, 6.8.0-1046.50, 6.8.0-1059.67, 6.8.0-1064.72~22.04.1, 6.8.0-1064.72, 6.8.1-1056.57~22.04.2, 6.8.1-1056.57
linux-lts-xenial (Ubuntu package) - update to 4.4.0-284.318~14.04.1
linux-kvm (Ubuntu package) - addressed in versions 4.4.0-1158.169, 5.4.0-1149.158, 5.4.0.1149.145
linux-aws (Ubuntu package) - addressed in versions 4.4.0-1157.163, 4.4.0-1195.210, 6.8.0-1061.64+1
linux-fips (Ubuntu package) - addressed in versions 4.4.0-1127.134, 5.15.0-190.200+fips1, 5.15.0-1110.116, 5.15.0.190.111, 5.15.0.1110.109, 6.8.0-136.136+fips2, 6.8.0-136.136.2~22.04.1, 6.8.0-136.136.2, 6.8.0-1058.61
linux-hwe-6.17 (Ubuntu package) - update to 6.17.0-42.42
linux-gcp-6.17 (Ubuntu package) - update to 6.17.0-1022.25
linux-oracle-6.17 (Ubuntu package) - update to 6.17.0-1020.20
linux-azure-6.17 (Ubuntu package) - update to 6.17.0-1022.22
linux-oem-6.17 (Ubuntu package) - update to 6.17.0-1032.32
linux-nvidia-6.17 (Ubuntu package) - update to 6.17.0-1031.31
linux-realtime-6.17 (Ubuntu package) - update to 6.17.0-1019.22
kernel-livepatch-6_4_0-150700_7_62-rt - 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-debuginfo - 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
kernel-devel - addressed in versions 5.10.0-321.0.0.223, 6.6.0-145.1.19.156, 6.6.0-145.3.17.150
perf - addressed in versions 5.10.0-321.0.0.223, 6.6.0-145.1.19.156, 6.6.0-145.3.17.150
perf-debuginfo - addressed in versions 5.10.0-321.0.0.223, 6.6.0-145.1.19.156, 6.6.0-145.3.17.150
python3-perf - addressed in versions 5.10.0-321.0.0.223, 6.6.0-145.1.19.156, 6.6.0-145.3.17.150
python3-perf-debuginfo - addressed in versions 5.10.0-321.0.0.223, 6.6.0-145.1.19.156, 6.6.0-145.3.17.150
kernel-tools-devel - addressed in versions 5.10.0-321.0.0.223, 6.6.0-145.1.19.156, 6.6.0-145.3.17.150
kernel-tools-debuginfo - addressed in versions 5.10.0-321.0.0.223, 6.6.0-145.1.19.156, 6.6.0-145.3.17.150
kernel-tools - addressed in versions 5.10.0-321.0.0.223, 6.6.0-145.1.19.156, 6.6.0-145.3.17.150
kernel-source - addressed in versions 5.10.0-321.0.0.223, 6.6.0-145.1.19.156, 6.6.0-145.3.17.150
kernel-headers - addressed in versions 5.10.0-321.0.0.223, 6.6.0-145.1.19.156, 6.6.0-145.3.17.150
kernel-debugsource - addressed in versions 5.10.0-321.0.0.223, 6.6.0-145.1.19.156, 6.6.0-145.3.17.150
kernel-debuginfo - addressed in versions 5.10.0-321.0.0.223, 6.6.0-145.1.19.156, 6.6.0-145.3.17.150
bpftool-debuginfo - addressed in versions 5.10.0-321.0.0.223, 6.6.0-145.1.19.156, 6.6.0-145.3.17.150
bpftool - addressed in versions 5.10.0-321.0.0.223, 6.6.0-145.1.19.156, 6.6.0-145.3.17.150
kernel - addressed in versions 5.10.0-321.0.0.223, 6.6.0-145.1.19.156, 6.6.0-145.3.17.150
kernel-source - addressed in versions 6.4.0-48.1, 6.4.0-150700.53.63.1
kernel-kvmsmall-debugsource - update to 6.4.0-48.1
kernel-kvmsmall-debuginfo - update to 6.4.0-48.1
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-devel - addressed in versions 6.4.0-48.1, 6.4.0-150700.53.63.1
kernel-macros - addressed in versions 6.4.0-48.1, 6.4.0-150700.53.63.1
kernel-default - 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-syms - addressed in versions 6.4.0-48.1, 6.4.0-150700.53.63.1
kernel-default-devel - addressed in versions 6.4.0-48.1, 6.4.0-150700.53.63.1
kernel-default-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-obs-build - addressed in versions 6.4.0-48.1, 6.4.0-150700.53.63.1
kernel-64kb-debugsource - 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-default-devel-debuginfo - addressed in versions 6.4.0-48.1, 6.4.0-150700.53.63.1
kernel-default-debuginfo - addressed in versions 6.4.0-48.1, 6.4.0-150700.53.63.1
kernel-default-base - addressed in versions 6.4.0-48.1.21.25, 6.4.0-150700.53.63.1.150700.17.37.1
ocfs2-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
kernel-rt-debugsource - update to 6.4.0-150700.7.62.1
kernel-syms-rt - update to 6.4.0-150700.7.62.1
kernel-rt-devel - update to 6.4.0-150700.7.62.1
cluster-md-kmp-rt-debuginfo - update to 6.4.0-150700.7.62.1
kernel-rt-devel-debuginfo - 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
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
gfs2-kmp-default-debuginfo - update to 6.4.0-150700.53.63.1
kernel-zfcpdump-debugsource - update to 6.4.0-150700.53.63.1
kernel-default-extra - update to 6.4.0-150700.53.63.1
kernel-default-livepatch-devel - update to 6.4.0-150700.53.63.1
cluster-md-kmp-default - update to 6.4.0-150700.53.63.1
dlm-kmp-default - update to 6.4.0-150700.53.63.1
ocfs2-kmp-default - update to 6.4.0-150700.53.63.1
cluster-md-kmp-default-debuginfo - update to 6.4.0-150700.53.63.1
gfs2-kmp-default - update to 6.4.0-150700.53.63.1
ocfs2-kmp-default-debuginfo - update to 6.4.0-150700.53.63.1
dlm-kmp-default-debuginfo - update to 6.4.0-150700.53.63.1
kernel-azure-devel - 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-zfcpdump-debuginfo - 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-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
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-extra-modules - update to 6.6.0-145.3.17.150
linux-aws-hwe (Ubuntu package) - addressed in versions 4.15.0-254.266~16.04.1, 4.15.0-1188.205~16.04.1, 4.15.0-1195.208~16.04.1, 4.15.0-1205.220~16.04.1
linux-oracle (Ubuntu package) - addressed in versions 4.15.0-1158.169~16.04.1, 4.15.0-1158.169, 4.15.0.1158.163, 5.15.0-1110.116, 5.15.0.1110.106
linux-azure (Ubuntu package) - addressed in versions 4.15.0-1205.220~14.04.1, 6.8.0-1063.71~22.04.1, 6.8.0-1063.71
linux-oracle-5.4 (Ubuntu package) - update to 5.4.0-1161.171~18.04.1
linux-aws-fips (Ubuntu package) - addressed in versions 5.4.0-1163.174+fips1, 5.4.0.1163.110
linux-gcp-fips (Ubuntu package) - addressed in versions 5.4.0-1165.174+fips1, 5.4.0.1165.107, 6.8.0-1064.72+fips1
linux-azure-5.4 (Ubuntu package) - addressed in versions 5.4.0-1167.173~18.04.1, 5.4.0-1167.173+fips1, 5.4.0.1167.103
linux-azure-5.15 (Ubuntu package) - addressed in versions 5.15.0-190.200~20.04.1, 5.15.0-1114.124, 5.15.0-1114.124+fips1, 5.15.0-1119.128~20.04.1, 5.15.0.1114.104, 5.15.0.1114.111
linux-lowlatency (Ubuntu package) - addressed in versions 5.15.0-190.200, 5.15.0.190.157
linux-nvidia-tegra-igx (Ubuntu package) - addressed in versions 5.15.0-1054.54, 5.15.0.1054.56
linux-raspi (Ubuntu package) - addressed in versions 5.15.0-1108.111, 5.15.0.1108.106, 6.8.0-1061.65, 6.8.0-2050.52
linux-aws-5.15 (Ubuntu package) - addressed in versions 5.15.0-1114.121~20.04.1, 5.15.0-1114.124~20.04.1
linux-azure-fde-5.15 (Ubuntu package) - update to 5.15.0-1118.127~20.04.1
linux (Debian package) - addressed in versions 6.1.170-1, 6.12.85-1
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, 6.8.0-1061.62~22.04.1, 6.8.0-1061.62
linux-oracle-6.8 (Ubuntu package) - update to 6.8.0-1058.61~22.04.1
linux-nvidia (Ubuntu package) - addressed in versions 6.8.0-1059.62~22.04.1, 6.8.0-1059.62, 6.8.0-1059.62.1
linux-aws-6.8 (Ubuntu package) - addressed in versions 6.8.0-1061.64~22.04.1, 6.8.0-1061.64+fips1
linux-azure-fde-6.8 (Ubuntu package) - update to 6.8.0-1062.69~22.04.1
linux-azure-fde (Ubuntu package) - update to 6.8.0-1062.69
linux-azure-fips (Ubuntu package) - update to 6.8.0-1063.71+fips2

External References

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