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Unscored CVE-2026-31681 EUVD-2026-25648GHSA-f822-mpgr-7cqx

netfilter: xt_multiport: validate range encoding in checkentry

Published Apr 25, 2026 · Updated Nov 10, 2026 · Assigned by Linux

Vendor: Linux Product: Linux Package: kernel Package: linux Package: linux Package: linux-allwinner-5.19 Package: linux-aws Package: linux-aws-5.0 Package: linux-aws-5.11 Package: linux-aws-5.13 Package: linux-aws-5.15 Package: linux-aws-5.19 Package: linux-aws-5.3 Package: linux-aws-5.4 Package: linux-aws-5.8 Package: linux-aws-6.14 Package: linux-aws-6.17 Package: linux-aws-6.2 Package: linux-aws-6.5 Package: linux-aws-6.8 Package: linux-aws-fips Package: linux-aws-hwe Package: linux-azure Package: linux-azure-4.15 Package: linux-azure-5.11 Package: linux-azure-5.13 Package: linux-azure-5.15 Package: linux-azure-5.19 Package: linux-azure-5.3 Package: linux-azure-5.4 Package: linux-azure-5.8 Package: linux-azure-6.11 Package: linux-azure-6.14 Package: linux-azure-6.17 Package: linux-azure-6.2 Package: linux-azure-6.5 Package: linux-azure-6.8 Package: linux-azure-edge Package: linux-azure-fde Package: linux-azure-fde-5.15 Package: linux-azure-fde-5.19 Package: linux-azure-fde-6.14 Package: linux-azure-fde-6.2 Package: linux-azure-fde-6.8 Package: linux-azure-fips Package: linux-azure-nvidia Package: linux-azure-nvidia-6.14 Package: linux-bluefield Package: linux-fips Package: linux-gcp Package: linux-gcp-4.15 Package: linux-gcp-5.11 Package: linux-gcp-5.13 Package: linux-gcp-5.15 Package: linux-gcp-5.19 Package: linux-gcp-5.3 Package: linux-gcp-5.4 Package: linux-gcp-5.8 Package: linux-gcp-6.11 Package: linux-gcp-6.14 Package: linux-gcp-6.17 Package: linux-gcp-6.2 Package: linux-gcp-6.5 Package: linux-gcp-6.8 Package: linux-gcp-fips Package: linux-gke Package: linux-gke-4.15 Package: linux-gke-5.15 Package: linux-gke-5.4 Package: linux-gkeop Package: linux-gkeop-5.15 Package: linux-gkeop-5.4 Package: linux-hwe Package: linux-hwe-5.11 Package: linux-hwe-5.13 Package: linux-hwe-5.15 Package: linux-hwe-5.19 Package: linux-hwe-5.4 Package: linux-hwe-5.8 Package: linux-hwe-6.11 Package: linux-hwe-6.14 Package: linux-hwe-6.17 Package: linux-hwe-6.2 Package: linux-hwe-6.5 Package: linux-hwe-6.8 Package: linux-hwe-edge Package: linux-ibm Package: linux-ibm-5.15 Package: linux-ibm-5.4 Package: linux-ibm-6.8 Package: linux-intel-5.13 Package: linux-intel-iot-realtime Package: linux-intel-iotg Package: linux-intel-iotg-5.15 Package: linux-iot Package: linux-kvm Package: linux-lowlatency Package: linux-lowlatency-hwe-5.15 Package: linux-lowlatency-hwe-5.19 Package: linux-lowlatency-hwe-6.11 Package: linux-lowlatency-hwe-6.2 Package: linux-lowlatency-hwe-6.5 Package: linux-lowlatency-hwe-6.8 Package: linux-lts-xenial Package: linux-nvidia Package: linux-nvidia-6.11 Package: linux-nvidia-6.17 Package: linux-nvidia-6.2 Package: linux-nvidia-6.5 Package: linux-nvidia-6.8 Package: linux-nvidia-lowlatency Package: linux-nvidia-tegra Package: linux-nvidia-tegra-5.15 Package: linux-nvidia-tegra-igx Package: linux-oem Package: linux-oem-5.10 Package: linux-oem-5.13 Package: linux-oem-5.14 Package: linux-oem-5.17 Package: linux-oem-5.6 Package: linux-oem-6.0 Package: linux-oem-6.1 Package: linux-oem-6.11 Package: linux-oem-6.14 Package: linux-oem-6.17 Package: linux-oem-6.5 Package: linux-oem-6.8 Package: linux-oracle Package: linux-oracle-5.0 Package: linux-oracle-5.11 Package: linux-oracle-5.13 Package: linux-oracle-5.15 Package: linux-oracle-5.3 Package: linux-oracle-5.4 Package: linux-oracle-5.8 Package: linux-oracle-6.14 Package: linux-oracle-6.17 Package: linux-oracle-6.5 Package: linux-oracle-6.8 Package: linux-raspi Package: linux-raspi-5.4 Package: linux-raspi-realtime Package: linux-raspi2 Package: linux-realtime Package: linux-realtime-6.14 Package: linux-realtime-6.17 Package: linux-realtime-6.8 Package: linux-riscv Package: linux-riscv-5.11 Package: linux-riscv-5.15 Package: linux-riscv-5.19 Package: linux-riscv-5.8 Package: linux-riscv-6.14 Package: linux-riscv-6.17 Package: linux-riscv-6.5 Package: linux-riscv-6.8 Package: linux-starfive-5.19 Package: linux-starfive-6.2 Package: linux-starfive-6.5 Package: linux-vmware Package: linux-xilinx Package: linux-xilinx-zynqmp Platform: Linux Ecosystem: Azure Linux Ecosystem: Debian Ecosystem: Ubuntu

Description

In the Linux kernel, the following vulnerability has been resolved:

netfilter: xt_multiport: validate range encoding in checkentry

ports_match_v1() treats any non-zero pflags entry as the start of a
port range and unconditionally consumes the next ports[] element as
the range end.

The checkentry path currently validates protocol, flags and count, but
it does not validate the range encoding itself. As a result, malformed
rules can mark the last slot as a range start or place two range starts
back to back, leaving ports_match_v1() to step past the last valid
ports[] element while interpreting the rule.

Reject malformed multiport v1 rules in checkentry by validating that
each range start has a following element and that the following element
is not itself marked as another range start.

Affected products

VendorProductAffectedFixed
Linux Linux 2.6.17 5.10.258

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 14 linux 6.19.14-1 —
Debian 13 linux 6.12.85-1 —
Debian 12 linux 6.1.176-1 —
ReleasePackageFixed inAdvisory
Ubuntu Nvidia-BlueField 24.04 LTS linux-bluefield 6.8.0-1028.33 —
Ubuntu Nvidia-BlueField 22.04 LTS linux-bluefield 5.15.0-1096.98 —
Ubuntu 26.04 LTS linux-nvidia 7.0.0-1006.6 —
Ubuntu 25.10 linux +8 No fix yet —
Ubuntu 24.04 LTS linux 6.8.0-136.136 USN-8567-1
Ubuntu 24.04 LTS linux-aws 6.8.0-1061.64 USN-8595-2
Ubuntu 24.04 LTS linux-azure 6.8.0-1063.71 USN-8606-1
Ubuntu 24.04 LTS linux-azure-fde 6.8.0-1062.69 USN-8607-1
Ubuntu 24.04 LTS linux-gcp 6.8.0-1064.72 USN-8567-1
Ubuntu 24.04 LTS linux-gke 6.8.0-1059.67 USN-8567-1
Ubuntu 24.04 LTS linux-gkeop 6.8.0-1046.50 USN-8567-1
Ubuntu 24.04 LTS linux-ibm 6.8.0-1061.62 USN-8574-3
Ubuntu 24.04 LTS linux-lowlatency 6.8.0-136.136.2 USN-8574-2
Ubuntu 24.04 LTS linux-nvidia 6.8.0-1059.62 USN-8596-1
Ubuntu 24.04 LTS linux-nvidia-lowlatency 6.8.0-1059.62.1 USN-8596-1
Ubuntu 24.04 LTS linux-nvidia-tegra 6.8.0-1030.31 USN-8574-3
Ubuntu 24.04 LTS linux-oracle 6.8.0-1058.61 USN-8574-2
Ubuntu 24.04 LTS linux-raspi 6.8.0-1061.65 USN-8665-1
Ubuntu 24.04 LTS linux-riscv +27 No fix yet —
Ubuntu 24.04 LTS linux-vmware 6.8.0-1008.8 —
Ubuntu 24.04 LTS linux-xilinx 6.8.0-1033.34 USN-8574-3
Show 19 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu 22.04 LTS linux 5.15.0-186.196 USN-8575-1
Ubuntu 22.04 LTS linux-aws 5.15.0-1112.119 USN-8575-2
Ubuntu 22.04 LTS linux-aws-6.8 6.8.0-1061.64~22.04.1 USN-8595-3
Ubuntu 22.04 LTS linux-azure +1 5.15.0-1117.126 USN-8610-1, USN-8575-3
Ubuntu 22.04 LTS linux-azure-6.8 6.8.0-1063.71~22.04.1 USN-8606-1
Ubuntu 22.04 LTS linux-azure-fde-6.8 6.8.0-1062.69~22.04.1 USN-8609-1
Ubuntu 22.04 LTS linux-gcp 5.15.0-1112.122 USN-8575-1
Ubuntu 22.04 LTS linux-gcp-6.8 6.8.0-1064.72~22.04.1 USN-8567-1
Ubuntu 22.04 LTS linux-gke 5.15.0-1108.114 USN-8575-1
Ubuntu 22.04 LTS linux-gkeop 5.15.0-1095.103 USN-8575-1
Ubuntu 22.04 LTS linux-hwe-6.8 6.8.0-136.136~22.04.1 USN-8619-1
Ubuntu 22.04 LTS linux-ibm 5.15.0-1106.110 USN-8575-2
Ubuntu 22.04 LTS linux-ibm-6.8 6.8.0-1061.62~22.04.1 USN-8574-3
Ubuntu 22.04 LTS linux-intel-iotg 5.15.0-1107.113 USN-8620-4
Ubuntu 22.04 LTS linux-kvm 5.15.0-1104.109 USN-8575-1
Ubuntu 22.04 LTS linux-lowlatency 5.15.0-184.194 USN-8575-1
Ubuntu 22.04 LTS linux-lowlatency-hwe-6.8 6.8.0-136.136.2~22.04.1 USN-8574-2
Ubuntu 22.04 LTS linux-nvidia 5.15.0-1107.108 USN-8575-2
Ubuntu 22.04 LTS linux-nvidia-6.8 6.8.0-1059.62~22.04.1 USN-8596-1
Ubuntu 22.04 LTS linux-nvidia-tegra 5.15.0-1064.66 USN-8576-2
Ubuntu 22.04 LTS linux-nvidia-tegra-igx 5.15.0-1053.53 USN-8576-2
Ubuntu 22.04 LTS linux-oracle 5.15.0-1109.115 USN-8575-3
Ubuntu 22.04 LTS linux-oracle-6.8 6.8.0-1058.61~22.04.1 USN-8595-1
Ubuntu 22.04 LTS linux-raspi 5.15.0-1106.109 USN-8668-2
Ubuntu 22.04 LTS linux-riscv +32 No fix yet —
Ubuntu 22.04 LTS linux-riscv-6.8 6.8.0-136.136~22.04.3 —
Ubuntu 22.04 LTS linux-xilinx-zynqmp 5.15.0-1075.79 USN-8575-1
Ubuntu 20.04 LTS linux-gke +28 No fix yet —
Ubuntu 18.04 LTS linux-gcp +14 No fix yet —
Ubuntu 16.04 LTS linux-hwe-edge No fix yet —
Ubuntu Pro Realtime 24.04 LTS linux-raspi-realtime 6.8.0-2050.52 USN-8665-1
Ubuntu Pro Realtime 24.04 LTS linux-realtime 6.8.1-1056.57 USN-8567-1
Ubuntu Pro Realtime 24.04 LTS linux-realtime-6.14 +1 No fix yet —
Ubuntu Pro Realtime 22.04 LTS linux-intel-iot-realtime 5.15.0-1104.106 USN-8620-3
Ubuntu Pro Realtime 22.04 LTS linux-realtime 5.15.0-1111.120 USN-8575-1
Ubuntu Pro Realtime 22.04 LTS linux-realtime-6.8 6.8.1-1056.57~22.04.2 USN-8567-1
Ubuntu Pro FIPS 20.04 LTS linux-fips +3 No fix yet —
Ubuntu Pro FIPS 18.04 LTS linux-fips +3 No fix yet —
Ubuntu Pro FIPS 16.04 LTS linux-fips No fix yet —
Ubuntu Pro FIPS-updates 24.04 LTS linux-aws-fips 6.8.0-1061.64+fips1 USN-8595-3
Ubuntu Pro FIPS-updates 24.04 LTS linux-azure-fips 6.8.0-1063.71+fips2 USN-8608-1
Ubuntu Pro FIPS-updates 24.04 LTS linux-fips 6.8.0-136.136+fips2 USN-8574-2
Ubuntu Pro FIPS-updates 24.04 LTS linux-gcp-fips 6.8.0-1064.72+fips1 USN-8574-1
Ubuntu Pro FIPS-updates 22.04 LTS linux-aws-fips 5.15.0-1112.119+fips1 USN-8575-2
Ubuntu Pro FIPS-updates 22.04 LTS linux-azure-fips 5.15.0-1117.126+fips1 USN-8620-2
Ubuntu Pro FIPS-updates 22.04 LTS linux-fips 5.15.0-186.196+fips1 USN-8575-2
Ubuntu Pro FIPS-updates 22.04 LTS linux-gcp-fips 5.15.0-1112.122+fips1 USN-8575-1
Ubuntu Pro FIPS-updates 20.04 LTS linux-fips +3 No fix yet —
Ubuntu Pro FIPS-updates 18.04 LTS linux-fips +3 No fix yet —
Ubuntu Pro FIPS-updates 16.04 LTS linux-fips No fix yet —
Ubuntu Pro FIPS-preview 22.04 LTS linux-fips +3 No fix yet —
Ubuntu Pro 20.04 LTS linux +10 No fix yet —
Ubuntu Pro 20.04 LTS linux-aws-5.15 5.15.0-1112.119~20.04.1 USN-8575-2
Ubuntu Pro 20.04 LTS linux-azure-5.15 5.15.0-1117.126~20.04.1 USN-8620-1
Ubuntu Pro 20.04 LTS linux-azure-fde-5.15 5.15.0-1117.126~20.04.2 USN-8620-1
Ubuntu Pro 20.04 LTS linux-gcp-5.15 5.15.0-1112.122~20.04.1 USN-8668-1
Ubuntu Pro 20.04 LTS linux-hwe-5.15 5.15.0-186.196~20.04.1 USN-8575-1
Ubuntu Pro 20.04 LTS linux-ibm-5.15 +1 5.15.0-1106.110~20.04.1 USN-8597-1
Ubuntu Pro 20.04 LTS linux-intel-iotg-5.15 5.15.0-1107.113~20.04.1 USN-8620-3
Ubuntu Pro 20.04 LTS linux-lowlatency-hwe-5.15 5.15.0-184.194~20.04.1 USN-8575-1
Ubuntu Pro 20.04 LTS linux-nvidia-tegra-5.15 5.15.0-1064.66~20.04.1 USN-8576-1
Ubuntu Pro 20.04 LTS linux-oracle-5.15 5.15.0-1109.115~20.04.1 USN-8620-1
Ubuntu Pro 18.04 LTS linux +12 No fix yet —
Ubuntu Pro 16.04 LTS linux +7 No fix yet —
Ubuntu Pro 14.04 LTS linux +3 No fix yet —
ReleasePackageFixed inAdvisory
SLES 15 SP7 kernel-64kb +7 6.4.0-150700.53.55.1 SUSE-SU-2026:2238-1
SLES 15 SP7 kernel-default-base 6.4.0-150700.53.55.1.150700.17.33.1 SUSE-SU-2026:2238-1
Show 2 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
SLE Micro 6.2 kernel-syms +1 6.12.0-160000.33.1 SUSE-SU-2026:21834-1
SLE Live Patching 15 SP7 kernel-default 6.4.0-150700.53.55.1 SUSE-SU-2026:2238-1
SLE Live Patching 15 SP7 kernel-livepatch-SLE15-SP7_Update_15 1-150700.15.3.1 SUSE-SU-2026:2238-1

Amazon Linux

ReleasePackageFixed inAdvisory
Amazon Linux 2023 kernel-livepatch-6.18.25-55.108 +2 1:1.0-0.amzn2023 ALAS2023-2026-1882, ALAS2023-2026-1695, ALAS2023-2026-1693
Amazon Linux 2023 perf +11 1:6.1.175-219.357.amzn2023 ALAS2023-2026-1882
Amazon Linux 2023 perf6.12 +11 1:6.12.83-113.160.amzn2023 ALAS2023-2026-1695
Amazon Linux 2023 perf6.18 +11 1:6.18.25-55.108.amzn2023 ALAS2023-2026-1693

Azure Linux

ReleasePackageFixed inAdvisory
Azure Linux 3 kernel 6.6.137.1-1 —

Oracle Linux

ReleasePackageFixed inAdvisory
Oracle Linux 9 kernel-uek +34 6.12.0-204.92.4.2.el10uek ELSA-2026-50372

Advisories 40

References