Improper access control in Linux kernel - CVE-2026-72247

Vulnerability identifier: #VU143353

CSH Severity: Medium

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

CVE-ID: CVE-2026-72247

CWE-ID: CWE-284

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to bypass connection counting limits.

The vulnerability exists due to improper access control in nf_conncount when processing connection tuples across conntrack zones. A remote attacker can send network traffic that creates connections with matching tuples in different zones to bypass connection counting limits.

The issue affects the tuple dedup logic in __nf_conncount_add(), where original-direction tuples are compared using an incorrect zone direction value.

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/35a56e2a46b90e6bd4ca816b80e9cb8d20dfc3ce
• https://git.kernel.org/stable/c/3cd9a5792cbea81139c24320986dd0db69e9b5d0
• https://git.kernel.org/stable/c/4f30a89c0ed2418719a1144881c2635b940b543d
• https://git.kernel.org/stable/c/6ff07ac5405bea4d4ead3559fc123f987576424a
• https://git.kernel.org/stable/c/78b5d6dbc860776161f9e9206b06ff8a01f531ab
• https://git.kernel.org/stable/c/7bdc3c0985ecf17b957811fedcc684acdf698acc
• https://git.kernel.org/stable/c/82fc35e0da9a91db9a034f8311f18f77a599ae3f
• https://git.kernel.org/stable/c/f62c41b4910e65da396ec9a8c40c1fe7fe82e449

• Improper access control in Linux kernel netfilter
• openEuler 24.03 LTS SP3 update for kernel