Out-of-bounds read in Linux kernel - CVE-2026-23397

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Main Vulnerability Database Vulnerabilities #VU124641

Out-of-bounds read in Linux kernel - CVE-2026-23397

Published: March 26, 2026


Vulnerability identifier: #VU124641
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-2026-23397
CWE-ID: CWE-125
Exploitation vector: Remote access
Exploit availability: No public exploit available

Vulnerability details

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

The vulnerability exists due to improper input validation in the nfnetlink_osf component when handling TCP option fingerprints. A remote attacker can send a specially crafted request to cause a denial of service.

Exploitation involves sending malicious TCP packets with zero-length options or MSS options with length less than 4, leading to null pointer dereference and out-of-bounds reads during packet matching.


Affected software

Linux kernel
Debian Linux
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
Basesystem Module
SUSE Linux Enterprise Live Patching
Public Cloud Module
Legacy Module
Development Tools 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-debuginfo
kernel-livepatch-SLE15-SP7_Update_15-debugsource
kernel-livepatch-6_4_0-150700_53_55-default
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-raspi (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)
linux (Debian package)
kernel-syms-rt
kernel-rt
kernel-source-rt
gfs2-kmp-rt-debuginfo
kernel-devel-rt
dlm-kmp-rt
ocfs2-kmp-rt-debuginfo
kernel-rt-devel
dlm-kmp-rt-debuginfo
kernel-rt-devel-debuginfo
kernel-rt-debuginfo
cluster-md-kmp-rt-debuginfo
kernel-rt-debugsource
gfs2-kmp-rt
ocfs2-kmp-rt
cluster-md-kmp-rt
kernel-obs-build
kernel-obs-build-debugsource
kernel-source
reiserfs-kmp-default-debuginfo
reiserfs-kmp-default
kernel-azure-debugsource
kernel-azure-debuginfo
kernel-azure-devel-debuginfo
kernel-azure-devel
kernel-default-extra-debuginfo
kernel-default-extra
kernel-default-livepatch
kernel-azure
kernel-default-livepatch-devel
kernel-64kb
gfs2-kmp-default
gfs2-kmp-default-debuginfo
dlm-kmp-default
cluster-md-kmp-default-debuginfo
kernel-default-debugsource
dlm-kmp-default-debuginfo
ocfs2-kmp-default-debuginfo
kernel-default-debuginfo
cluster-md-kmp-default
kernel-syms
ocfs2-kmp-default
kernel-default
kernel-64kb-devel-debuginfo
kernel-64kb-debugsource
kernel-64kb-devel
kernel-64kb-debuginfo
kernel-default-devel-debuginfo
kernel-default-devel
kernel-devel
kernel-macros
kernel-zfcpdump
kernel-zfcpdump-debuginfo
kernel-zfcpdump-debugsource
kernel-docs
kernel-default-base
perf
kernel-tools-devel
kernel-tools-debuginfo
kernel-debuginfo
kernel-tools
kernel-headers
kernel-debugsource
bpftool-debuginfo
bpftool
kernel
python3-perf
python3-perf-debuginfo
perf-debuginfo
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-azure-fde-6.8 (Ubuntu package)
linux-gcp-fips (Ubuntu package)

How to mitigate CVE-2026-23397

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-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
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-raspi (Ubuntu package) - addressed in versions 5.15.0.1106.104, 5.15.0-1106.109, 6.8.0-1061.65, 6.8.0-2050.52
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
linux (Debian package) - addressed in versions 6.1.170-1, 6.12.85-1
kernel-syms-rt - 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
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-devel - 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-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
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
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-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-azure - 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
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
kernel-default-debugsource - update to 6.4.0-150700.53.55.1
dlm-kmp-default-debuginfo - update to 6.4.0-150700.53.55.1
ocfs2-kmp-default-debuginfo - update to 6.4.0-150700.53.55.1
kernel-default-debuginfo - update to 6.4.0-150700.53.55.1
cluster-md-kmp-default - update to 6.4.0-150700.53.55.1
kernel-syms - 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-64kb-devel-debuginfo - update to 6.4.0-150700.53.55.1
kernel-64kb-debugsource - update to 6.4.0-150700.53.55.1
kernel-64kb-devel - update to 6.4.0-150700.53.55.1
kernel-64kb-debuginfo - update to 6.4.0-150700.53.55.1
kernel-default-devel-debuginfo - update to 6.4.0-150700.53.55.1
kernel-default-devel - update to 6.4.0-150700.53.55.1
kernel-devel - update to 6.4.0-150700.53.55.1
kernel-macros - update to 6.4.0-150700.53.55.1
kernel-zfcpdump - update to 6.4.0-150700.53.55.1
kernel-zfcpdump-debuginfo - update to 6.4.0-150700.53.55.1
kernel-zfcpdump-debugsource - update to 6.4.0-150700.53.55.1
kernel-docs - 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
perf - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-tools-devel - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-tools-debuginfo - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-debuginfo - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-tools - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-source - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-headers - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-devel - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-debugsource - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
bpftool-debuginfo - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
bpftool - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
python3-perf - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
python3-perf-debuginfo - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
perf-debuginfo - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-extra-modules - update to 6.6.0-145.0.2.143
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-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

External References

Related Security Bulletins