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
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise Workstation Extension 15
SUSE Linux Enterprise High Availability Extension 15
SUSE Linux Enterprise Desktop 15
Basesystem Module
SUSE Linux Enterprise Live Patching
Public Cloud Module
Legacy Module
Development Tools Module
SUSE Real Time Module
Ubuntu
openEuler
linux-nvidia-tegra (Ubuntu package)
linux-nvidia-tegra-igx (Ubuntu package)
linux-nvidia-tegra-5.15 (Ubuntu package)
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)
kernel-livepatch-SLE15-SP7-RT_Update_21-debugsource
kernel-livepatch-6_4_0-150700_7_78-rt
kernel-livepatch-6_4_0-150700_7_78-rt-debuginfo
kernel-livepatch-6_4_0-150700_53_84-default-debuginfo
kernel-livepatch-SLE15-SP7_Update_22-debugsource
kernel-livepatch-6_4_0-150700_53_84-default
kernel-rt-debugsource
kernel-source-rt
ocfs2-kmp-rt
gfs2-kmp-rt-debuginfo
gfs2-kmp-rt
dlm-kmp-rt-debuginfo
cluster-md-kmp-rt
ocfs2-kmp-rt-debuginfo
kernel-syms-rt
dlm-kmp-rt
kernel-rt-devel
kernel-rt-devel-debuginfo
kernel-rt-debuginfo
cluster-md-kmp-rt-debuginfo
kernel-devel-rt
kernel-rt
kernel-zfcpdump-debuginfo
kernel-64kb
kernel-64kb-debuginfo
kernel-64kb-devel-debuginfo
kernel-64kb-debugsource
kernel-64kb-devel
kernel-docs
kernel-syms
kernel-obs-build
kernel-obs-build-debugsource
kernel-azure-debugsource
kernel-source
kernel-default-debuginfo
cluster-md-kmp-default-debuginfo
ocfs2-kmp-default
gfs2-kmp-default
dlm-kmp-default
gfs2-kmp-default-debuginfo
cluster-md-kmp-default
kernel-default-debugsource
dlm-kmp-default-debuginfo
kernel-zfcpdump-debugsource
ocfs2-kmp-default-debuginfo
kernel-default
kernel-default-devel
kernel-default-devel-debuginfo
kernel-devel
kernel-macros
kernel-zfcpdump
reiserfs-kmp-default-debuginfo
kernel-default-extra-debuginfo
kernel-default-extra
kernel-azure-devel-debuginfo
kernel-azure-debuginfo
kernel-azure-devel
reiserfs-kmp-default
kernel-azure
kernel-default-livepatch
kernel-default-livepatch-devel
kernel-default-base
bpftool-debuginfo
kernel-debuginfo
bpftool
kernel-debugsource
kernel-extra-modules
kernel-headers
kernel-tools
kernel-tools-debuginfo
kernel-tools-devel
perf
perf-debuginfo
python3-perf
python3-perf-debuginfo
kernel
linux-nvidia (Ubuntu package)
linux-oracle-5.15 (Ubuntu package)
linux-gcp-5.15 (Ubuntu package)
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-nvidia-tegra (Ubuntu package) - addressed in versions 5.15.0-1070.72, 6.8.0-1036.39+1
linux-nvidia-tegra-igx (Ubuntu package) - update to 5.15.0-1059.59
linux-nvidia-tegra-5.15 (Ubuntu package) - update to 5.15.0-1070.72~20.04.1
linux (Ubuntu package) - addressed in versions 5.15.0-195.205~20.04.1, 5.15.0-195.205, 5.15.0-198.208~20.04.1, 5.15.0-198.208+fips1, 5.15.0-1080.84, 5.15.0-1100.108, 5.15.0-1109.111, 5.15.0-1109.114, 5.15.0-1111.115~20.04.1, 5.15.0-1111.115, 5.15.0-1112.118~20.04.1, 5.15.0-1112.118, 5.15.0-1113.119, 5.15.0-1114.120, 5.15.0-1116.125~20.04.1, 5.15.0-1117.124~20.04.1, 5.15.0-1117.124, 5.15.0-1117.124+fips1, 5.15.0-1122.131~20.04.1, 5.15.0-1123.132~20.04.1, 5.15.0-1123.132, 5.15.0-1123.132+fips1, 5.15.0.195.160, 5.15.0.195.205~20.04.1, 5.15.0.198.114, 5.15.0.198.171, 5.15.0.198.208~20.04.1, 5.15.0.1080.83~20.04.1, 5.15.0.1100.99, 5.15.0.1109.105, 5.15.0.1109.113, 5.15.0.1111.108, 5.15.0.1111.115~20.04.1, 5.15.0.1112.111, 5.15.0.1112.118~20.04.1, 5.15.0.1113.112, 5.15.0.1114.110, 5.15.0.1116.120, 5.15.0.1117.113, 5.15.0.1117.120, 5.15.0.1117.124~20.04.1, 5.15.0.1122.131~20.04.1, 5.15.0.1123.107, 5.15.0.1123.121, 5.15.0.1123.132~20.04.1, 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) - addressed in versions 5.15.0-1118.128, 5.15.0-1118.128+fips1, 5.15.0.1118.107, 5.15.0.1118.115, 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) - addressed in versions 5.15.0-1122.131, 5.15.0.1122.131, 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
kernel-livepatch-SLE15-SP7-RT_Update_21-debugsource - update to 1-150700.1.3.1
kernel-livepatch-6_4_0-150700_7_78-rt - update to 1-150700.1.3.1
kernel-livepatch-6_4_0-150700_7_78-rt-debuginfo - update to 1-150700.1.3.1
kernel-livepatch-6_4_0-150700_53_84-default-debuginfo - update to 1-150700.15.3.1
kernel-livepatch-SLE15-SP7_Update_22-debugsource - update to 1-150700.15.3.1
kernel-livepatch-6_4_0-150700_53_84-default - update to 1-150700.15.3.1
kernel-rt-debugsource - update to 6.4.0-150700.7.78.1
kernel-source-rt - update to 6.4.0-150700.7.78.1
ocfs2-kmp-rt - update to 6.4.0-150700.7.78.1
gfs2-kmp-rt-debuginfo - update to 6.4.0-150700.7.78.1
gfs2-kmp-rt - update to 6.4.0-150700.7.78.1
dlm-kmp-rt-debuginfo - update to 6.4.0-150700.7.78.1
cluster-md-kmp-rt - update to 6.4.0-150700.7.78.1
ocfs2-kmp-rt-debuginfo - update to 6.4.0-150700.7.78.1
kernel-syms-rt - update to 6.4.0-150700.7.78.1
dlm-kmp-rt - update to 6.4.0-150700.7.78.1
kernel-rt-devel - update to 6.4.0-150700.7.78.1
kernel-rt-devel-debuginfo - update to 6.4.0-150700.7.78.1
kernel-rt-debuginfo - update to 6.4.0-150700.7.78.1
cluster-md-kmp-rt-debuginfo - update to 6.4.0-150700.7.78.1
kernel-devel-rt - update to 6.4.0-150700.7.78.1
kernel-rt - update to 6.4.0-150700.7.78.1
kernel-zfcpdump-debuginfo - update to 6.4.0-150700.53.84.1
kernel-64kb - update to 6.4.0-150700.53.84.1
kernel-64kb-debuginfo - update to 6.4.0-150700.53.84.1
kernel-64kb-devel-debuginfo - update to 6.4.0-150700.53.84.1
kernel-64kb-debugsource - update to 6.4.0-150700.53.84.1
kernel-64kb-devel - update to 6.4.0-150700.53.84.1
kernel-docs - update to 6.4.0-150700.53.84.1
kernel-syms - update to 6.4.0-150700.53.84.1
kernel-obs-build - update to 6.4.0-150700.53.84.1
kernel-obs-build-debugsource - update to 6.4.0-150700.53.84.1
kernel-azure-debugsource - update to 6.4.0-150700.53.84.1
kernel-source - update to 6.4.0-150700.53.84.1
kernel-default-debuginfo - update to 6.4.0-150700.53.84.1
cluster-md-kmp-default-debuginfo - update to 6.4.0-150700.53.84.1
ocfs2-kmp-default - update to 6.4.0-150700.53.84.1
gfs2-kmp-default - update to 6.4.0-150700.53.84.1
dlm-kmp-default - update to 6.4.0-150700.53.84.1
gfs2-kmp-default-debuginfo - update to 6.4.0-150700.53.84.1
cluster-md-kmp-default - update to 6.4.0-150700.53.84.1
kernel-default-debugsource - update to 6.4.0-150700.53.84.1
dlm-kmp-default-debuginfo - update to 6.4.0-150700.53.84.1
kernel-zfcpdump-debugsource - update to 6.4.0-150700.53.84.1
ocfs2-kmp-default-debuginfo - update to 6.4.0-150700.53.84.1
kernel-default - update to 6.4.0-150700.53.84.1
kernel-default-devel - update to 6.4.0-150700.53.84.1
kernel-default-devel-debuginfo - update to 6.4.0-150700.53.84.1
kernel-devel - update to 6.4.0-150700.53.84.1
kernel-macros - update to 6.4.0-150700.53.84.1
kernel-zfcpdump - update to 6.4.0-150700.53.84.1
reiserfs-kmp-default-debuginfo - update to 6.4.0-150700.53.84.1
kernel-default-extra-debuginfo - update to 6.4.0-150700.53.84.1
kernel-default-extra - update to 6.4.0-150700.53.84.1
kernel-azure-devel-debuginfo - update to 6.4.0-150700.53.84.1
kernel-azure-debuginfo - update to 6.4.0-150700.53.84.1
kernel-azure-devel - update to 6.4.0-150700.53.84.1
reiserfs-kmp-default - update to 6.4.0-150700.53.84.1
kernel-azure - update to 6.4.0-150700.53.84.1
kernel-default-livepatch - update to 6.4.0-150700.53.84.1
kernel-default-livepatch-devel - update to 6.4.0-150700.53.84.1
kernel-default-base - update to 6.4.0-150700.53.84.1.150700.17.47.1
bpftool-debuginfo - update to 6.6.0-145.3.31.162
kernel-debuginfo - update to 6.6.0-145.3.31.162
bpftool - 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
kernel - update to 6.6.0-145.3.31.162
linux-nvidia (Ubuntu package) - addressed in versions 5.15.0-1112.113, 5.15.0.1112.112
linux-oracle-5.15 (Ubuntu package) - addressed in versions 5.15.0-1114.120~20.04.1, 5.15.0.1114.120~20.04.1
linux-gcp-5.15 (Ubuntu package) - addressed in versions 5.15.0-1118.128~20.04.1, 5.15.0.1118.128~20.04.1
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/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
• Ubuntu update for linux-gcp-7.0
• Ubuntu update for linux-nvidia
• Ubuntu update for linux-azure-7.0
• Ubuntu update for linux-nvidia-tegra
• Ubuntu update for linux
• Ubuntu update for linux-azure
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux-azure-fde
• Ubuntu update for linux-gcp
• Ubuntu update for linux-gcp-5.15
• Ubuntu update for linux-oracle-5.15
• Ubuntu update for linux
• SUSE update for the Linux Kernel
• SUSE update for the Linux Kernel
• Ubuntu update for linux, linux-aws, linux-aws-fips and more
• Ubuntu update for linux-azure, linux-azure-fde, linux-azure-fips
• Ubuntu update for linux-nvidia-tegra, linux-nvidia-tegra-5.15, linux-nvidia-tegra-igx