Stack-based buffer overflow in Linux kernel - CVE-2026-53267

Vulnerability identifier: #VU135489

CSH Severity: Low

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

CVE-ID: CVE-2026-53267

CWE-ID: CWE-121

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to cause memory corruption.

The vulnerability exists due to a stack-based buffer overflow in nft_ct_get_eval and nft_ct_get_fast_eval in the netfilter nft_ct subsystem when processing a crafted nftables rule that uses a template conntrack object. A local user can create a crafted rule sequence to cause memory corruption.

The issue is triggered when a conntrack template created by a preceding expression is treated as a real conntrack entry by a subsequent expression on the same skb.

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

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
bpftool - addressed in versions 5.10.0-326.0.0.227, 6.6.0-145.1.20.157
kernel - addressed in versions 5.10.0-326.0.0.227, 6.6.0-145.1.20.157
python3-perf-debuginfo - addressed in versions 5.10.0-326.0.0.227, 6.6.0-145.1.20.157
python3-perf - addressed in versions 5.10.0-326.0.0.227, 6.6.0-145.1.20.157
perf-debuginfo - addressed in versions 5.10.0-326.0.0.227, 6.6.0-145.1.20.157
perf - addressed in versions 5.10.0-326.0.0.227, 6.6.0-145.1.20.157
kernel-tools-devel - addressed in versions 5.10.0-326.0.0.227, 6.6.0-145.1.20.157
kernel-tools-debuginfo - addressed in versions 5.10.0-326.0.0.227, 6.6.0-145.1.20.157
kernel-tools - addressed in versions 5.10.0-326.0.0.227, 6.6.0-145.1.20.157
kernel-source - addressed in versions 5.10.0-326.0.0.227, 6.6.0-145.1.20.157
kernel-headers - addressed in versions 5.10.0-326.0.0.227, 6.6.0-145.1.20.157
kernel-devel - addressed in versions 5.10.0-326.0.0.227, 6.6.0-145.1.20.157
kernel-debugsource - addressed in versions 5.10.0-326.0.0.227, 6.6.0-145.1.20.157
kernel-debuginfo - addressed in versions 5.10.0-326.0.0.227, 6.6.0-145.1.20.157
bpftool-debuginfo - addressed in versions 5.10.0-326.0.0.227, 6.6.0-145.1.20.157

• https://git.kernel.org/stable/c/2e154b5f53f1b0b490c7b8b02499f90feb86b1d5
• https://git.kernel.org/stable/c/3027ecbdb5fdf9200251c21d4818e4c447ef78e1
• https://git.kernel.org/stable/c/8470f676eadeab99132708acb1a85915664d6115
• https://git.kernel.org/stable/c/af80f78ce984649e1698b841cd33f4fa505ad828
• https://git.kernel.org/stable/c/f071b0bf078146368d18e4eec386bf2ddc0ab7e0

• Stack-based buffer overflow in Linux kernel netfilter
• openEuler 22.03 LTS SP4 update for kernel
• openEuler 24.03 LTS SP1 update for kernel