Type conversion in Linux kernel - CVE-2026-80637

Vulnerability identifier: #VU146223

CSH Severity: Medium

CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-80637

CWE-ID: CWE-704

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 improper handling of unaligned memory access in synproxy timestamp adjustment in netfilter synproxy when processing crafted TCP packets with timestamp options. A remote attacker can send specially crafted network packets to cause a denial of service.

The issue may lead to a crash on strict alignment architectures.

Linux kernel
SUSE Linux Enterprise Server 12 SP5 LTSS Extended
SUSE Linux Enterprise Server 12 SP5
SUSE Linux Enterprise Server for SAP Applications 12
SUSE Linux Enterprise Server 12
SUSE Linux Enterprise High Performance Computing 12
SUSE Linux Micro Extras
SUSE Linux Micro
SUSE Linux Enterprise Live Patching
openEuler
Ubuntu
linux (Ubuntu package)
linux-lowlatency (Ubuntu package)
linux-azure (Ubuntu package)
linux-gcp (Ubuntu package)
linux-aws (Ubuntu package)
linux-ibm (Ubuntu package)
linux-oracle (Ubuntu package)
linux-azure-fde (Ubuntu package)
linux-realtime (Ubuntu package)
linux-fips (Ubuntu package)
linux-gkeop (Ubuntu package)
linux-gke (Ubuntu package)
linux-azure-fips (Ubuntu package)
linux-aws-fips (Ubuntu package)
linux-gcp-fips (Ubuntu package)
kgraft-patch-4_12_14-122_339-default
ocfs2-kmp-default-debuginfo
ocfs2-kmp-default
gfs2-kmp-default-debuginfo
kernel-default-base
kernel-default-base-debuginfo
dlm-kmp-default
kernel-default-devel
dlm-kmp-default-debuginfo
kernel-syms
gfs2-kmp-default
cluster-md-kmp-default-debuginfo
kernel-default-kgraft-devel
kernel-default-kgraft
kernel-default-debugsource
kernel-default-debuginfo
kernel-default
cluster-md-kmp-default
kernel-default-devel-debuginfo
kernel-source
kernel-macros
kernel-devel
kernel-default-man
kernel-obs-build-debugsource
kernel-obs-build
kernel-64kb-devel
kernel-64kb-debugsource
kernel-64kb
bpftool
kernel-headers
python3-perf-debuginfo
python3-perf
perf-debuginfo
perf
kernel-tools-devel
kernel-tools-debuginfo
kernel-tools
kernel-extra-modules
kernel-debugsource
kernel-debuginfo
bpftool-debuginfo
kernel
linux-gcp-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux-azure-7.0 (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux (Ubuntu package) - addressed in versions 6.8.0-147.147, 7.0.0-38.38, 7.0.0-38.38.1, 7.0.0-1008.9, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14, 7.0.0-1015.15
linux-lowlatency (Ubuntu package) - update to 6.8.0-147.147.1
linux-azure (Ubuntu package) - addressed in versions 6.8.0-1071.79, 7.0.0-1016.16, 7.0.0-1017.17
linux-gcp (Ubuntu package) - update to 6.8.0-1071.79
linux-aws (Ubuntu package) - update to 6.8.0-1067.70
linux-ibm (Ubuntu package) - update to 6.8.0-1067.68
linux-oracle (Ubuntu package) - update to 6.8.0-1064.67
linux-azure-fde (Ubuntu package) - update to 6.8.0-1069.76
linux-realtime (Ubuntu package) - update to 6.8.1-1062.63
linux-fips (Ubuntu package) - update to 6.8.0-147.147+fips1
linux-gkeop (Ubuntu package) - update to 6.8.0-1052.56
linux-gke (Ubuntu package) - update to 6.8.0-1066.74
linux-azure-fips (Ubuntu package) - update to 6.8.0-1071.79+fips1
linux-aws-fips (Ubuntu package) - update to 6.8.0-1067.70+fips1
linux-gcp-fips (Ubuntu package) - update to 6.8.0-1071.79+fips1
kgraft-patch-4_12_14-122_339-default - update to 1-8.3.1
ocfs2-kmp-default-debuginfo - update to 4.12.14-122.339.1
ocfs2-kmp-default - update to 4.12.14-122.339.1
gfs2-kmp-default-debuginfo - update to 4.12.14-122.339.1
kernel-default-base - update to 4.12.14-122.339.1
kernel-default-base-debuginfo - update to 4.12.14-122.339.1
dlm-kmp-default - update to 4.12.14-122.339.1
kernel-default-devel - addressed in versions 4.12.14-122.339.1, 6.4.0-159998.55.1
dlm-kmp-default-debuginfo - update to 4.12.14-122.339.1
kernel-syms - addressed in versions 4.12.14-122.339.1, 6.4.0-159998.55.1
gfs2-kmp-default - update to 4.12.14-122.339.1
cluster-md-kmp-default-debuginfo - update to 4.12.14-122.339.1
kernel-default-kgraft-devel - update to 4.12.14-122.339.1
kernel-default-kgraft - update to 4.12.14-122.339.1
kernel-default-debugsource - addressed in versions 4.12.14-122.339.1, 6.4.0-159998.55.1
kernel-default-debuginfo - update to 4.12.14-122.339.1
kernel-default - addressed in versions 4.12.14-122.339.1, 6.4.0-159998.55.1
cluster-md-kmp-default - update to 4.12.14-122.339.1
kernel-default-devel-debuginfo - addressed in versions 4.12.14-122.339.1, 6.4.0-159998.55.1
kernel-source - update to 4.12.14-122.339.1
kernel-macros - update to 4.12.14-122.339.1
kernel-devel - update to 4.12.14-122.339.1
kernel-default-man - update to 4.12.14-122.339.1
kernel-obs-build-debugsource - update to 6.4.0-159998.55.1
kernel-obs-build - update to 6.4.0-159998.55.1
kernel-64kb-devel - update to 6.4.0-159998.55.1
kernel-64kb-debugsource - update to 6.4.0-159998.55.1
kernel-64kb - update to 6.4.0-159998.55.1
bpftool - update to 6.6.0-145.3.31.162
kernel-headers - update to 6.6.0-145.3.31.162
python3-perf-debuginfo - update to 6.6.0-145.3.31.162
python3-perf - update to 6.6.0-145.3.31.162
perf-debuginfo - update to 6.6.0-145.3.31.162
perf - update to 6.6.0-145.3.31.162
kernel-tools-devel - update to 6.6.0-145.3.31.162
kernel-tools-debuginfo - update to 6.6.0-145.3.31.162
kernel-tools - update to 6.6.0-145.3.31.162
kernel-source - update to 6.6.0-145.3.31.162
kernel-extra-modules - update to 6.6.0-145.3.31.162
kernel-devel - update to 6.6.0-145.3.31.162
kernel-debugsource - update to 6.6.0-145.3.31.162
kernel-debuginfo - update to 6.6.0-145.3.31.162
bpftool-debuginfo - update to 6.6.0-145.3.31.162
kernel - update to 6.6.0-145.3.31.162
linux-gcp-7.0 (Ubuntu package) - addressed in versions 7.0.0-38.38~24.04.4, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1015.15
linux-azure-7.0 (Ubuntu package) - addressed in versions 7.0.0-1016.16~24.04.1, 7.0.0-1017.17~24.04.1

• https://git.kernel.org/stable/c/2b8e7aaa38002d8ee2f48d87b1f392eadd8e98c4
• https://git.kernel.org/stable/c/5c9c67cf7a3d16051dfb90e98836f530964dfb8e
• https://git.kernel.org/stable/c/992c20bc8a4aba220c8b95b467d049289778dad6
• https://git.kernel.org/stable/c/ea3d2caa5bfacf5db5c1cad521ca5d9144edd9a7

• Type conversion in Linux kernel netfilter
• openEuler 24.03 LTS SP3 update for kernel
• Ubuntu update for linux-gcp-7.0
• Ubuntu update for linux-azure-7.0
• Ubuntu update for linux
• Ubuntu update for linux-azure
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-aws-fips and more
• Ubuntu update for linux-azure, linux-azure-fde, linux-azure-fips
• SUSE update for the Linux Kernel
• SUSE update for the Linux Kernel