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
openEuler
kernel
bpftool
bpftool-debuginfo
kernel-debuginfo
kernel-debugsource
kernel-devel
kernel-extra-modules
kernel-headers
kernel-source
kernel-tools
kernel-tools-debuginfo
kernel-tools-devel
perf
perf-debuginfo
python3-perf
python3-perf-debuginfo

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
kernel - update to 6.6.0-145.3.31.162
bpftool - update to 6.6.0-145.3.31.162
bpftool-debuginfo - update to 6.6.0-145.3.31.162
kernel-debuginfo - update to 6.6.0-145.3.31.162
kernel-debugsource - update to 6.6.0-145.3.31.162
kernel-devel - update to 6.6.0-145.3.31.162
kernel-extra-modules - update to 6.6.0-145.3.31.162
kernel-headers - update to 6.6.0-145.3.31.162
kernel-source - update to 6.6.0-145.3.31.162
kernel-tools - update to 6.6.0-145.3.31.162
kernel-tools-debuginfo - update to 6.6.0-145.3.31.162
kernel-tools-devel - update to 6.6.0-145.3.31.162
perf - update to 6.6.0-145.3.31.162
perf-debuginfo - update to 6.6.0-145.3.31.162
python3-perf - update to 6.6.0-145.3.31.162
python3-perf-debuginfo - update to 6.6.0-145.3.31.162

• 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