NULL pointer dereference in Linux kernel - CVE-2026-23442

Vulnerability identifier: #VU124929

CSH Severity: Medium

CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-23442

CWE-ID: CWE-476

Exploitation vector: Remote access

Exploit availability: No public exploit available

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

The vulnerability exists due to a NULL pointer dereference in seg6_hmac_validate_skb() and ipv6_srh_rcv() when processing SRv6 paths on a device without IPv6 configuration. A remote attacker can send specially crafted IPv6 traffic to cause a denial of service.

The issue occurs when __in6_dev_get() returns NULL, such as on a device with no IPv6 configuration, including after device unregister or when the MTU is below the IPv6 minimum MTU.

Linux kernel
Debian Linux
SUSE Linux Enterprise Server 12 SP5
SUSE Linux Enterprise Server 12 SP5 LTSS Extended
SUSE Linux Enterprise High Performance Computing 12
SUSE Linux Enterprise Server 12
SUSE Linux Enterprise Server for SAP Applications 12
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Workstation Extension 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise High Availability Extension 15
SUSE Linux Enterprise Desktop 15
SUSE Linux Enterprise Live Patching
SUSE Real Time Module
Basesystem Module
Development Tools Module
Legacy Module
Public Cloud Module
Ubuntu
openEuler
kgraft-patch-4_12_14-122_310-default
kernel-livepatch-6_4_0-150700_7_54-rt
kernel-livepatch-SLE15-SP7-RT_Update_15-debugsource
kernel-livepatch-6_4_0-150700_7_54-rt-debuginfo
kernel-livepatch-6_4_0-150700_53_55-default-debuginfo
kernel-livepatch-SLE15-SP7_Update_15-debugsource
kernel-livepatch-6_4_0-150700_53_55-default
kernel-syms
kernel-default-base
cluster-md-kmp-default-debuginfo
dlm-kmp-default-debuginfo
kernel-default-devel
ocfs2-kmp-default
kernel-default-base-debuginfo
ocfs2-kmp-default-debuginfo
cluster-md-kmp-default
dlm-kmp-default
kernel-default-debugsource
gfs2-kmp-default
gfs2-kmp-default-debuginfo
kernel-default-debuginfo
kernel-default
kernel-source
kernel-devel
kernel-macros
kernel-default-man
kernel-default-devel-debuginfo
kernel-default-kgraft
kernel-default-kgraft-devel
linux (Ubuntu package)
linux-aws (Ubuntu package)
linux-nvidia-tegra (Ubuntu package)
linux-nvidia-tegra-5.15 (Ubuntu package)
linux-intel-iot-realtime (Ubuntu package)
linux-ibm-5.15 (Ubuntu package)
linux-intel-iotg (Ubuntu package)
linux-azure (Ubuntu package)
linux-azure-5.15 (Ubuntu package)
linux-gcp-5.15 (Ubuntu package)
linux-azure-fips (Ubuntu package)
linux-azure-fde (Ubuntu package)
dlm-kmp-rt-debuginfo
dlm-kmp-rt
ocfs2-kmp-rt-debuginfo
kernel-rt
kernel-source-rt
gfs2-kmp-rt-debuginfo
kernel-devel-rt
kernel-rt-devel
kernel-rt-devel-debuginfo
kernel-rt-debuginfo
cluster-md-kmp-rt-debuginfo
kernel-rt-debugsource
gfs2-kmp-rt
kernel-syms-rt
ocfs2-kmp-rt
cluster-md-kmp-rt
kernel-obs-build
kernel-obs-build-debugsource
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-64kb
kernel-64kb-debugsource
kernel-zfcpdump-debugsource
kernel-zfcpdump-debuginfo
kernel-zfcpdump
kernel-docs
kernel-64kb-debuginfo
kernel-64kb-devel
kernel-64kb-devel-debuginfo
perf-debuginfo
perf
kernel-tools-devel
python3-perf
bpftool
python3-perf-debuginfo
kernel-tools-debuginfo
kernel-tools
kernel-headers
kernel-debugsource
kernel-debuginfo
bpftool-debuginfo
kernel
kernel-extra-modules
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-raspi (Ubuntu package)
linux-azure-fde-6.8 (Ubuntu package)
linux-gcp-fips (Ubuntu package)
linux (Debian package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
kgraft-patch-4_12_14-122_310-default - update to 1-8.3.1
kernel-livepatch-6_4_0-150700_7_54-rt - 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-debuginfo - update to 1-150700.1.3.1
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
kernel-livepatch-6_4_0-150700_53_55-default - update to 1-150700.15.3.1
kernel-syms - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1
kernel-default-base - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1.150700.17.33.1
cluster-md-kmp-default-debuginfo - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1
dlm-kmp-default-debuginfo - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1
kernel-default-devel - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1
ocfs2-kmp-default - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1
kernel-default-base-debuginfo - update to 4.12.14-122.310.1
ocfs2-kmp-default-debuginfo - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1
cluster-md-kmp-default - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1
dlm-kmp-default - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1
kernel-default-debugsource - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1
gfs2-kmp-default - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1
gfs2-kmp-default-debuginfo - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1
kernel-default-debuginfo - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1
kernel-default - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1
kernel-source - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1
kernel-devel - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1
kernel-macros - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1
kernel-default-man - update to 4.12.14-122.310.1
kernel-default-devel-debuginfo - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1
kernel-default-kgraft - update to 4.12.14-122.310.1
kernel-default-kgraft-devel - update to 4.12.14-122.310.1
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
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
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-intel-iot-realtime (Ubuntu package) - addressed in versions 5.15.0-1104.106, 5.15.0.1104.108, 5.15.0-1107.113~20.04.1
linux-ibm-5.15 (Ubuntu package) - update to 5.15.0-1106.110~20.04.1
linux-intel-iotg (Ubuntu package) - addressed in versions 5.15.0.1107.106, 5.15.0-1107.113
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
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-gcp-5.15 (Ubuntu package) - update to 5.15.0-1112.122~20.04.1
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
dlm-kmp-rt-debuginfo - update to 6.4.0-150700.7.54.1
dlm-kmp-rt - update to 6.4.0-150700.7.54.1
ocfs2-kmp-rt-debuginfo - update to 6.4.0-150700.7.54.1
kernel-rt - update to 6.4.0-150700.7.54.1
kernel-source-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-rt-devel - update to 6.4.0-150700.7.54.1
kernel-rt-devel-debuginfo - update to 6.4.0-150700.7.54.1
kernel-rt-debuginfo - 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-debugsource - update to 6.4.0-150700.7.54.1
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
kernel-obs-build - update to 6.4.0-150700.53.55.1
kernel-obs-build-debugsource - 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-64kb - update to 6.4.0-150700.53.55.1
kernel-64kb-debugsource - 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-docs - 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-devel-debuginfo - update to 6.4.0-150700.53.55.1
perf-debuginfo - addressed in versions 6.6.0-145.0.7.134, 6.6.0-145.0.7.146, 6.6.0-145.0.9.140
perf - addressed in versions 6.6.0-145.0.7.134, 6.6.0-145.0.7.146, 6.6.0-145.0.9.140
kernel-tools-devel - addressed in versions 6.6.0-145.0.7.134, 6.6.0-145.0.7.146, 6.6.0-145.0.9.140
python3-perf - addressed in versions 6.6.0-145.0.7.134, 6.6.0-145.0.7.146, 6.6.0-145.0.9.140
bpftool - addressed in versions 6.6.0-145.0.7.134, 6.6.0-145.0.7.146, 6.6.0-145.0.9.140
python3-perf-debuginfo - addressed in versions 6.6.0-145.0.7.134, 6.6.0-145.0.7.146, 6.6.0-145.0.9.140
kernel-tools-debuginfo - addressed in versions 6.6.0-145.0.7.134, 6.6.0-145.0.7.146, 6.6.0-145.0.9.140
kernel-tools - addressed in versions 6.6.0-145.0.7.134, 6.6.0-145.0.7.146, 6.6.0-145.0.9.140
kernel-source - addressed in versions 6.6.0-145.0.7.134, 6.6.0-145.0.7.146, 6.6.0-145.0.9.140
kernel-headers - addressed in versions 6.6.0-145.0.7.134, 6.6.0-145.0.7.146, 6.6.0-145.0.9.140
kernel-devel - addressed in versions 6.6.0-145.0.7.134, 6.6.0-145.0.7.146, 6.6.0-145.0.9.140
kernel-debugsource - addressed in versions 6.6.0-145.0.7.134, 6.6.0-145.0.7.146, 6.6.0-145.0.9.140
kernel-debuginfo - addressed in versions 6.6.0-145.0.7.134, 6.6.0-145.0.7.146, 6.6.0-145.0.9.140
bpftool-debuginfo - addressed in versions 6.6.0-145.0.7.134, 6.6.0-145.0.7.146, 6.6.0-145.0.9.140
kernel - addressed in versions 6.6.0-145.0.7.134, 6.6.0-145.0.7.146, 6.6.0-145.0.9.140
kernel-extra-modules - update to 6.6.0-145.0.9.140
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-raspi (Ubuntu package) - addressed in versions 6.8.0-1061.65, 6.8.0-2050.52
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 6.12.85-1

• https://git.kernel.org/stable/c/06413793526251870e20402c39930804f14d59c0
• https://git.kernel.org/stable/c/a25853c9feea7bbf31d157ff6e004d2d3b4f7f13

• NULL pointer dereference in Linux kernel ipv6
• openEuler 24.03 LTS update for kernel
• openEuler 24.03 LTS SP1 update for kernel
• openEuler 24.03 LTS SP3 update for kernel
• Debian update for linux
• SUSE update for the Linux Kernel
• SUSE update for the Linux Kernel
• SUSE update for the Linux Kernel
• Ubuntu update for linux
• Ubuntu update for linux-gcp-fips
• Ubuntu update for linux-nvidia-tegra-5.15
• Ubuntu update for linux
• Ubuntu update for linux-oracle-6.8
• Ubuntu update for linux-fips
• Ubuntu update for linux-ibm-5.15
• Ubuntu update for linux-nvidia-tegra
• Ubuntu update for linux-aws
• Ubuntu update for linux-nvidia
• Ubuntu update for linux-azure-fde
• Ubuntu update for linux-azure
• Ubuntu update for linux-azure-fde-6.8
• Ubuntu update for linux-azure-fips
• Ubuntu update for linux-azure-fde
• Ubuntu update for linux-azure
• Ubuntu update for linux-aws
• Ubuntu update for linux-azure-5.15
• Ubuntu update for linux-hwe-6.8
• Ubuntu update for linux-aws-6.8
• Ubuntu update for linux-ibm
• Ubuntu update for linux-azure-fips
• Ubuntu update for linux-intel-iot-realtime
• Ubuntu update for linux-intel-iotg
• Ubuntu update for linux-raspi
• Ubuntu update for linux-gcp-5.15