Use of uninitialized resource in Linux kernel - CVE-2026-53218

Vulnerability identifier: #VU135564

CSH Severity: Low

CVSS v4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-53218

CWE-ID: CWE-908

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to disclose sensitive information.

The vulnerability exists due to an uninitialized memory exposure in nft_exthdr_init and the nft_exthdr evaluation paths when processing a userspace request with the NFT_EXTHDR_F_PRESENT flag set and an invalid length value. A local user can supply a crafted netfilter expression that causes uninitialized stack data from nft_regs to be retained in registers and disclose sensitive information.

The issue occurs because the initialized register bitmap can mark more bytes as written than the evaluation paths actually store when the presence flag is used.

Linux kernel
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise Workstation Extension 15
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise High Availability Extension 15
SUSE Linux Enterprise Desktop 15
Public Cloud Module
Development Tools Module
Basesystem Module
SUSE Linux Enterprise Live Patching
SUSE Real Time Module
Legacy Module
openEuler
Ubuntu
kernel-livepatch-6_4_0-150700_7_67-rt
kernel-livepatch-SLE15-SP7-RT_Update_18-debugsource
kernel-livepatch-6_4_0-150700_7_67-rt-debuginfo
kernel-livepatch-SLE15-SP7_Update_19-debugsource
kernel-livepatch-6_4_0-150700_53_73-default
kernel-livepatch-6_4_0-150700_53_73-default-debuginfo
ocfs2-kmp-rt
kernel-rt-devel-debuginfo
kernel-rt
kernel-source-rt
kernel-devel-rt
kernel-rt-debuginfo
dlm-kmp-rt
cluster-md-kmp-rt
kernel-rt-debugsource
ocfs2-kmp-rt-debuginfo
kernel-syms-rt
cluster-md-kmp-rt-debuginfo
gfs2-kmp-rt-debuginfo
kernel-rt-devel
dlm-kmp-rt-debuginfo
gfs2-kmp-rt
kernel-syms
kernel-docs
kernel-source
kernel-macros
kernel-devel
kernel-default-devel
kernel-obs-build
kernel-obs-build-debugsource
kernel-default-devel-debuginfo
reiserfs-kmp-default
reiserfs-kmp-default-debuginfo
kernel-default-extra-debuginfo
kernel-default-extra
kernel-64kb-debugsource
kernel-default-livepatch-devel
kernel-default-debuginfo
kernel-default-debugsource
kernel-default-livepatch
kernel-azure
kernel-azure-debuginfo
kernel-azure-devel-debuginfo
kernel-azure-devel
kernel-azure-debugsource
kernel-default
ocfs2-kmp-default-debuginfo
kernel-64kb
kernel-64kb-devel
kernel-64kb-devel-debuginfo
kernel-64kb-debuginfo
kernel-zfcpdump-debugsource
kernel-zfcpdump-debuginfo
kernel-zfcpdump
ocfs2-kmp-default
dlm-kmp-default-debuginfo
cluster-md-kmp-default-debuginfo
dlm-kmp-default
cluster-md-kmp-default
gfs2-kmp-default
gfs2-kmp-default-debuginfo
kernel-default-base
kernel-tools
python3-perf-debuginfo
python3-perf
perf-debuginfo
perf
kernel-tools-devel
kernel-tools-debuginfo
kernel-headers
kernel-debugsource
kernel-debuginfo
bpftool-debuginfo
bpftool
kernel
linux (Ubuntu package)
linux-azure (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux-oracle-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux-ibm (Ubuntu package)
linux-azure-7.0 (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-nvidia-7.0 (Ubuntu package)
linux-raspi (Ubuntu package)
linux-nvidia-bos (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
kernel-livepatch-6_4_0-150700_7_67-rt - update to 1-150700.1.5.1
kernel-livepatch-SLE15-SP7-RT_Update_18-debugsource - update to 1-150700.1.5.1
kernel-livepatch-6_4_0-150700_7_67-rt-debuginfo - update to 1-150700.1.5.1
kernel-livepatch-SLE15-SP7_Update_19-debugsource - update to 1-150700.15.3.4
kernel-livepatch-6_4_0-150700_53_73-default - update to 1-150700.15.3.4
kernel-livepatch-6_4_0-150700_53_73-default-debuginfo - update to 1-150700.15.3.4
ocfs2-kmp-rt - update to 6.4.0-150700.7.67.1
kernel-rt-devel-debuginfo - update to 6.4.0-150700.7.67.1
kernel-rt - update to 6.4.0-150700.7.67.1
kernel-source-rt - update to 6.4.0-150700.7.67.1
kernel-devel-rt - update to 6.4.0-150700.7.67.1
kernel-rt-debuginfo - update to 6.4.0-150700.7.67.1
dlm-kmp-rt - update to 6.4.0-150700.7.67.1
cluster-md-kmp-rt - update to 6.4.0-150700.7.67.1
kernel-rt-debugsource - update to 6.4.0-150700.7.67.1
ocfs2-kmp-rt-debuginfo - update to 6.4.0-150700.7.67.1
kernel-syms-rt - update to 6.4.0-150700.7.67.1
cluster-md-kmp-rt-debuginfo - update to 6.4.0-150700.7.67.1
gfs2-kmp-rt-debuginfo - update to 6.4.0-150700.7.67.1
kernel-rt-devel - update to 6.4.0-150700.7.67.1
dlm-kmp-rt-debuginfo - update to 6.4.0-150700.7.67.1
gfs2-kmp-rt - update to 6.4.0-150700.7.67.1
kernel-syms - update to 6.4.0-150700.53.73.1
kernel-docs - update to 6.4.0-150700.53.73.1
kernel-source - update to 6.4.0-150700.53.73.1
kernel-macros - update to 6.4.0-150700.53.73.1
kernel-devel - update to 6.4.0-150700.53.73.1
kernel-default-devel - update to 6.4.0-150700.53.73.2
kernel-obs-build - update to 6.4.0-150700.53.73.2
kernel-obs-build-debugsource - update to 6.4.0-150700.53.73.2
kernel-default-devel-debuginfo - update to 6.4.0-150700.53.73.2
reiserfs-kmp-default - update to 6.4.0-150700.53.73.2
reiserfs-kmp-default-debuginfo - update to 6.4.0-150700.53.73.2
kernel-default-extra-debuginfo - update to 6.4.0-150700.53.73.2
kernel-default-extra - update to 6.4.0-150700.53.73.2
kernel-64kb-debugsource - update to 6.4.0-150700.53.73.2
kernel-default-livepatch-devel - update to 6.4.0-150700.53.73.2
kernel-default-debuginfo - update to 6.4.0-150700.53.73.2
kernel-default-debugsource - update to 6.4.0-150700.53.73.2
kernel-default-livepatch - update to 6.4.0-150700.53.73.2
kernel-azure - update to 6.4.0-150700.53.73.2
kernel-azure-debuginfo - update to 6.4.0-150700.53.73.2
kernel-azure-devel-debuginfo - update to 6.4.0-150700.53.73.2
kernel-azure-devel - update to 6.4.0-150700.53.73.2
kernel-azure-debugsource - update to 6.4.0-150700.53.73.2
kernel-default - update to 6.4.0-150700.53.73.2
ocfs2-kmp-default-debuginfo - update to 6.4.0-150700.53.73.2
kernel-64kb - update to 6.4.0-150700.53.73.2
kernel-64kb-devel - update to 6.4.0-150700.53.73.2
kernel-64kb-devel-debuginfo - update to 6.4.0-150700.53.73.2
kernel-64kb-debuginfo - update to 6.4.0-150700.53.73.2
kernel-zfcpdump-debugsource - update to 6.4.0-150700.53.73.2
kernel-zfcpdump-debuginfo - update to 6.4.0-150700.53.73.2
kernel-zfcpdump - update to 6.4.0-150700.53.73.2
ocfs2-kmp-default - update to 6.4.0-150700.53.73.2
dlm-kmp-default-debuginfo - update to 6.4.0-150700.53.73.2
cluster-md-kmp-default-debuginfo - update to 6.4.0-150700.53.73.2
dlm-kmp-default - update to 6.4.0-150700.53.73.2
cluster-md-kmp-default - update to 6.4.0-150700.53.73.2
gfs2-kmp-default - update to 6.4.0-150700.53.73.2
gfs2-kmp-default-debuginfo - update to 6.4.0-150700.53.73.2
kernel-default-base - update to 6.4.0-150700.53.73.2.150700.17.41.4
kernel-tools - update to 6.6.0-145.1.20.157
python3-perf-debuginfo - update to 6.6.0-145.1.20.157
python3-perf - update to 6.6.0-145.1.20.157
perf-debuginfo - update to 6.6.0-145.1.20.157
perf - update to 6.6.0-145.1.20.157
kernel-tools-devel - update to 6.6.0-145.1.20.157
kernel-tools-debuginfo - update to 6.6.0-145.1.20.157
kernel-headers - update to 6.6.0-145.1.20.157
kernel-devel - update to 6.6.0-145.1.20.157
kernel-debugsource - update to 6.6.0-145.1.20.157
kernel-debuginfo - update to 6.6.0-145.1.20.157
bpftool-debuginfo - update to 6.6.0-145.1.20.157
bpftool - update to 6.6.0-145.1.20.157
kernel - update to 6.6.0-145.1.20.157
kernel-source - update to 6.6.0-145.1.20.157
linux (Ubuntu package) - addressed in versions 7.0.0-31.31, 7.0.0-31.31.1, 7.0.0-31.31~24.04.1, 7.0.0-1006.7, 7.0.0-1011.11~24.04.1, 7.0.0-1012.12, 7.0.0-1012.12~24.04.1
linux-azure (Ubuntu package) - addressed in versions 7.0.0-1011.11, 7.0.0-1014.14
linux-gcp-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-oracle-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1013.13
linux-ibm (Ubuntu package) - update to 7.0.0-1013.13
linux-azure-7.0 (Ubuntu package) - update to 7.0.0-1014.14~24.04.1
linux-nvidia (Ubuntu package) - update to 7.0.0-1018.18
linux-nvidia-7.0 (Ubuntu package) - update to 7.0.0-1018.18~24.04.1
linux-raspi (Ubuntu package) - update to 7.0.0-1019.19
linux-nvidia-bos (Ubuntu package) - update to 7.0.0-2018.18

• https://git.kernel.org/stable/c/19748967d59c31d24d21d40b728570788310b237
• https://git.kernel.org/stable/c/46fc15a044e9938e7ea77786fb37edd2cd74f031
• https://git.kernel.org/stable/c/67b27434c43b68a97becda98c9f0c8cf6cba2134
• https://git.kernel.org/stable/c/772cecf198da732faebb5dcfc46d66a505be8495
• https://git.kernel.org/stable/c/78069a6d8bc86c9e036eb82c2af4a19cc1871a53
• https://git.kernel.org/stable/c/8738b1b6d0e639ca1fc0f61516afd3557ac4ecc6
• https://git.kernel.org/stable/c/cd513e43b4b2bd1de39e2367bc4261c699a8652f
• https://git.kernel.org/stable/c/f08fb3d42fd3aad0b7a263da3ac3ebaf0845e265

• Use of uninitialized resource in Linux kernel netfilter
• SUSE update for the Linux Kernel
• SUSE update for the Linux Kernel
• openEuler 24.03 LTS SP1 update for kernel
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux
• Ubuntu update for linux-gcp-7.0
• Ubuntu update for linux-oracle-7.0
• Ubuntu update for linux-azure
• Ubuntu update for linux-azure-7.0
• Ubuntu update for linux-nvidia
• Ubuntu update for linux-nvidia-bos
• Ubuntu update for linux-ibm
• Ubuntu update for linux-raspi
• Ubuntu update for linux-nvidia-7.0