UBUNTU-CVE-2026-72254: Null Pointer Dereference

Published Aug 15, 2026
·
Updated

In the Linux kernel, the following vulnerability has been resolved: netfilter: nftfib: reject fib expression on the netdev egress hook A fib expression in a netdev egress base chain dereferences nftin(pkt), NULL on the transmit path, causing a NULL pointer dereference at eval. nftfibvalidate() masks the hook with NFINET values, but netdev hook numbers are a separate enum that aliases them (NFNETDEVEGRESS == NFINETLOCALIN), so an egress chain passes validation and then faults. Add nftfibnetdevvalidate() that limits each result/flag to the netdev hook where the device it reads exists: the input-device cases (OIF, OIFNAME, ADDRTYPE with FIIF) to ingress, the output-device case (ADDRTYPE with FOIF) to egress, ADDRTYPE with no device flag to both. Also restrict nftfibvalidate() to NFPROTOIPV4/IPV6/INET so its NFINET masks are not applied to another family's hooks.

Affected Software

161 affected componentsFixes available
ubuntu/linux-hwe-edge*
ubuntu/linux-aws-5.0*
ubuntu/linux-aws-5.3*
ubuntu/linux-azure*
ubuntu/linux-azure-5.3*
ubuntu/linux-azure-edge*
ubuntu/linux-gcp*
ubuntu/linux-gcp-5.3*
ubuntu/linux-gke-4.15*
ubuntu/linux-gke-5.4*
ubuntu/linux-gkeop-5.4*
ubuntu/linux-hwe*
ubuntu/linux-hwe-edge*
ubuntu/linux-oem*
ubuntu/linux-oracle-5.0*
ubuntu/linux-oracle-5.3*
ubuntu/linux-aws-5.11*
ubuntu/linux-aws-5.13*
ubuntu/linux-aws-5.8*
ubuntu/linux-azure-5.11*
ubuntu/linux-azure-5.13*
ubuntu/linux-azure-5.8*
ubuntu/linux-azure-fde*
ubuntu/linux-gcp-5.11*
ubuntu/linux-gcp-5.13*
ubuntu/linux-gcp-5.8*
ubuntu/linux-gke*
ubuntu/linux-gke-5.15*
ubuntu/linux-gkeop*
ubuntu/linux-gkeop-5.15*
ubuntu/linux-hwe-5.11*
ubuntu/linux-hwe-5.13*
ubuntu/linux-hwe-5.8*
ubuntu/linux-intel-5.13*
ubuntu/linux-oem-5.10*
ubuntu/linux-oem-5.13*
ubuntu/linux-oem-5.6*
ubuntu/linux-oracle-5.11*
ubuntu/linux-oracle-5.13*
ubuntu/linux-oracle-5.8*
ubuntu/linux-raspi2*
ubuntu/linux-riscv*
ubuntu/linux-riscv-5.11*
ubuntu/linux-riscv-5.8*
ubuntu/linux-allwinner-5.19*
ubuntu/linux-aws-5.19*
ubuntu/linux-aws-6.2*
ubuntu/linux-aws-6.5*
ubuntu/linux-aws-6.8*
ubuntu/linux-azure-5.19*
ubuntu/linux-azure-6.2*
ubuntu/linux-azure-6.5*
ubuntu/linux-azure-6.8*
ubuntu/linux-azure-fde-5.19*
ubuntu/linux-azure-fde-6.2*
ubuntu/linux-azure-fde-6.8*
ubuntu/linux-gcp-5.19*
ubuntu/linux-gcp-6.2*
ubuntu/linux-gcp-6.5*
ubuntu/linux-gcp-6.8*
ubuntu/linux-hwe-5.19*
ubuntu/linux-hwe-6.2*
ubuntu/linux-hwe-6.5*
ubuntu/linux-ibm-6.8*
ubuntu/linux-intel-iot-realtime*
ubuntu/linux-lowlatency-hwe-5.19*
ubuntu/linux-lowlatency-hwe-6.2*
ubuntu/linux-lowlatency-hwe-6.5*
ubuntu/linux-lowlatency-hwe-6.8*
ubuntu/linux-nvidia-6.2*
ubuntu/linux-nvidia-6.5*
ubuntu/linux-nvidia-6.8*
ubuntu/linux-oem-5.17*
ubuntu/linux-oem-6.0*
ubuntu/linux-oem-6.1*
ubuntu/linux-oem-6.5*
ubuntu/linux-oracle-6.5*
ubuntu/linux-oracle-6.8*
ubuntu/linux-realtime*
ubuntu/linux-riscv*
ubuntu/linux-riscv-5.19*
ubuntu/linux-riscv-6.5*
ubuntu/linux-riscv-6.8*
ubuntu/linux-starfive-5.19*
ubuntu/linux-starfive-6.2*
ubuntu/linux-starfive-6.5*
ubuntu/linux-realtime-6.8*
ubuntu/linux<6.8.0-147.147
6.8.0-147.147
ubuntu/linux-aws<6.8.0-1067.70
6.8.0-1067.70
ubuntu/linux-aws-6.14*
ubuntu/linux-aws-6.17*
ubuntu/linux-aws-7.0<7.0.0-1014.14~24.04.1
7.0.0-1014.14~24.04.1
ubuntu/linux-azure<6.8.0-1071.79
6.8.0-1071.79
ubuntu/linux-azure-6.11*
ubuntu/linux-azure-6.14*
ubuntu/linux-azure-6.17*
ubuntu/linux-azure-7.0<7.0.0-1017.17~24.04.1
7.0.0-1017.17~24.04.1
ubuntu/linux-azure-fde<6.8.0-1069.76
6.8.0-1069.76
ubuntu/linux-azure-fde-6.14*
ubuntu/linux-azure-fde-6.17*
ubuntu/linux-azure-fde-7.0<7.0.0-1016.16~24.04.1
7.0.0-1016.16~24.04.1
ubuntu/linux-azure-nvidia*
ubuntu/linux-azure-nvidia-6.14*
ubuntu/linux-gcp<6.8.0-1071.79
6.8.0-1071.79
ubuntu/linux-gcp-6.11*
ubuntu/linux-gcp-6.14*
ubuntu/linux-gcp-7.0<7.0.0-1014.14~24.04.1
7.0.0-1014.14~24.04.1
ubuntu/linux-gke<6.8.0-1066.74
6.8.0-1066.74
ubuntu/linux-gkeop<6.8.0-1052.56
6.8.0-1052.56
ubuntu/linux-hwe-6.11*
ubuntu/linux-hwe-6.14*
ubuntu/linux-hwe-6.17*
ubuntu/linux-hwe-7.0<7.0.0-38.38~24.04.4
7.0.0-38.38~24.04.4
ubuntu/linux-ibm<6.8.0-1067.68
6.8.0-1067.68
ubuntu/linux-lowlatency<6.8.0-147.147.1
6.8.0-147.147.1
ubuntu/linux-lowlatency-hwe-6.11*
ubuntu/linux-nvidia*
ubuntu/linux-nvidia-6.11*
ubuntu/linux-nvidia-6.17*
ubuntu/linux-nvidia-7.0*
ubuntu/linux-nvidia-lowlatency*
ubuntu/linux-nvidia-tegra<6.8.0-1036.39
6.8.0-1036.39
ubuntu/linux-oem-6.11*
ubuntu/linux-oem-6.14*
ubuntu/linux-oem-6.17*
ubuntu/linux-oem-6.8*
ubuntu/linux-oracle<6.8.0-1064.67
6.8.0-1064.67
ubuntu/linux-oracle-6.14*
ubuntu/linux-oracle-6.17*
ubuntu/linux-oracle-7.0<7.0.0-1013.13~24.04.1
7.0.0-1013.13~24.04.1
ubuntu/linux-raspi*
ubuntu/linux-raspi-realtime*
ubuntu/linux-realtime*
ubuntu/linux-riscv*
ubuntu/linux-riscv-6.14*
ubuntu/linux-riscv-6.17*
ubuntu/linux-riscv-7.0<7.0.0-38.38.1~24.04.1
7.0.0-38.38.1~24.04.1
ubuntu/linux-xilinx*
ubuntu/linux-bluefield<6.8.0-1033.38
6.8.0-1033.38
ubuntu/linux-raspi-realtime*
ubuntu/linux-realtime<6.8.1-1062.63
6.8.1-1062.63
ubuntu/linux-realtime-6.14*
ubuntu/linux-realtime-6.17*
ubuntu/linux-aws-fips<6.8.0-1067.70+fips1
6.8.0-1067.70+fips1
ubuntu/linux-azure-fips<6.8.0-1071.79+fips1
6.8.0-1071.79+fips1
ubuntu/linux-fips<6.8.0-147.147+fips1
6.8.0-147.147+fips1
ubuntu/linux-gcp-fips<6.8.0-1071.79+fips1
6.8.0-1071.79+fips1
ubuntu/linux<7.0.0-38.38
7.0.0-38.38
ubuntu/linux-aws<7.0.0-1014.14
7.0.0-1014.14
ubuntu/linux-azure<7.0.0-1017.17
7.0.0-1017.17
ubuntu/linux-azure-fde<7.0.0-1016.16
7.0.0-1016.16
ubuntu/linux-gcp<7.0.0-1014.14
7.0.0-1014.14
ubuntu/linux-gke<7.0.0-1008.9
7.0.0-1008.9
ubuntu/linux-ibm<7.0.0-1015.15
7.0.0-1015.15
ubuntu/linux-nvidia*
ubuntu/linux-nvidia-bos*
ubuntu/linux-oem-7.0<7.0.0-1015.15
7.0.0-1015.15
ubuntu/linux-oracle<7.0.0-1013.13
7.0.0-1013.13
ubuntu/linux-raspi*
ubuntu/linux-realtime<7.0.0-38.38.1
7.0.0-38.38.1
ubuntu/linux-riscv<7.0.0-38.38.1
7.0.0-38.38.1

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade ubuntu/linux to a version that resolves this vulnerability.

    Fixed in 6.8.0-147.147
  2. Upgrade

    Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.

    Fixed in 6.8.0-1067.70
  3. Upgrade

    Upgrade ubuntu/linux-aws-7.0 to a version that resolves this vulnerability.

    Fixed in 7.0.0-1014.14~24.04.1
  4. Upgrade

    Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.

    Fixed in 6.8.0-1071.79
  5. Upgrade

    Upgrade ubuntu/linux-azure-7.0 to a version that resolves this vulnerability.

    Fixed in 7.0.0-1017.17~24.04.1
  6. Upgrade

    Upgrade ubuntu/linux-azure-fde to a version that resolves this vulnerability.

    Fixed in 6.8.0-1069.76
  7. Upgrade

    Upgrade ubuntu/linux-azure-fde-7.0 to a version that resolves this vulnerability.

    Fixed in 7.0.0-1016.16~24.04.1
  8. Upgrade

    Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.

    Fixed in 6.8.0-1071.79
  9. Upgrade

    Upgrade ubuntu/linux-gcp-7.0 to a version that resolves this vulnerability.

    Fixed in 7.0.0-1014.14~24.04.1
  10. Upgrade

    Upgrade ubuntu/linux-gke to a version that resolves this vulnerability.

    Fixed in 6.8.0-1066.74
  11. Upgrade

    Upgrade ubuntu/linux-gkeop to a version that resolves this vulnerability.

    Fixed in 6.8.0-1052.56
  12. Upgrade

    Upgrade ubuntu/linux-hwe-7.0 to a version that resolves this vulnerability.

    Fixed in 7.0.0-38.38~24.04.4
  13. Upgrade

    Upgrade ubuntu/linux-ibm to a version that resolves this vulnerability.

    Fixed in 6.8.0-1067.68
  14. Upgrade

    Upgrade ubuntu/linux-lowlatency to a version that resolves this vulnerability.

    Fixed in 6.8.0-147.147.1
  15. Upgrade

    Upgrade ubuntu/linux-nvidia-tegra to a version that resolves this vulnerability.

    Fixed in 6.8.0-1036.39
  16. Upgrade

    Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.

    Fixed in 6.8.0-1064.67
  17. Upgrade

    Upgrade ubuntu/linux-oracle-7.0 to a version that resolves this vulnerability.

    Fixed in 7.0.0-1013.13~24.04.1
  18. Upgrade

    Upgrade ubuntu/linux-riscv-7.0 to a version that resolves this vulnerability.

    Fixed in 7.0.0-38.38.1~24.04.1
  19. Upgrade

    Upgrade ubuntu/linux-bluefield to a version that resolves this vulnerability.

    Fixed in 6.8.0-1033.38
  20. Upgrade

    Upgrade ubuntu/linux-realtime to a version that resolves this vulnerability.

    Fixed in 6.8.1-1062.63
  21. Upgrade

    Upgrade ubuntu/linux-aws-fips to a version that resolves this vulnerability.

    Fixed in 6.8.0-1067.70+fips1
  22. Upgrade

    Upgrade ubuntu/linux-azure-fips to a version that resolves this vulnerability.

    Fixed in 6.8.0-1071.79+fips1
  23. Upgrade

    Upgrade ubuntu/linux-fips to a version that resolves this vulnerability.

    Fixed in 6.8.0-147.147+fips1
  24. Upgrade

    Upgrade ubuntu/linux-gcp-fips to a version that resolves this vulnerability.

    Fixed in 6.8.0-1071.79+fips1
  25. Upgrade

    Upgrade ubuntu/linux to a version that resolves this vulnerability.

    Fixed in 7.0.0-38.38
  26. Upgrade

    Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.

    Fixed in 7.0.0-1014.14
  27. Upgrade

    Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.

    Fixed in 7.0.0-1017.17
  28. Upgrade

    Upgrade ubuntu/linux-azure-fde to a version that resolves this vulnerability.

    Fixed in 7.0.0-1016.16
  29. Upgrade

    Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.

    Fixed in 7.0.0-1014.14
  30. Upgrade

    Upgrade ubuntu/linux-gke to a version that resolves this vulnerability.

    Fixed in 7.0.0-1008.9
  31. Upgrade

    Upgrade ubuntu/linux-ibm to a version that resolves this vulnerability.

    Fixed in 7.0.0-1015.15
  32. Upgrade

    Upgrade ubuntu/linux-oem-7.0 to a version that resolves this vulnerability.

    Fixed in 7.0.0-1015.15
  33. Upgrade

    Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.

    Fixed in 7.0.0-1013.13
  34. Upgrade

    Upgrade ubuntu/linux-realtime to a version that resolves this vulnerability.

    Fixed in 7.0.0-38.38.1
  35. Upgrade

    Upgrade ubuntu/linux-riscv to a version that resolves this vulnerability.

    Fixed in 7.0.0-38.38.1
  36. Compensating control

    Update nft_fib validation to add nft_fib_netdev_validate(): allow OIF, OIFNAME, and ADDRTYPE with F_IIF only on the netdev ingress hook; allow ADDRTYPE with F_OIF only on the netdev egress hook; allow ADDRTYPE with no device flag on both hooks. Also restrict nft_fib_validate() to NFPROTO_IPV4, NFPROTO_IPV6, and NFPROTO_INET so NF_INET_* masks are not applied to other protocol families.

Event History

Aug 15, 2026
CVE Published
via OSV·06:21 AM
Data Sourced
via OSV·06:21 AM
DescriptionSeverityAffected Software

Frequently Asked Questions

1

Which systems and configurations are exposed?

The affected software list includes Ubuntu linux-riscv, linux-realtime, linux-azure, linux-gcp, linux-azure-fde, linux-gke, linux-hwe-edge, and linux-gkeop packages. Exposure requires an nftables netdev egress base chain containing a FIB expression that is evaluated on the transmit path.

2

What is the practical impact of successful triggering?

The expression can dereference a NULL input packet device pointer during evaluation, causing a kernel fault. The supplied CVSS vector indicates an availability-only impact, with no stated confidentiality or integrity impact.

3

Does exploitation require authentication or user interaction?

The supplied CVSS vector rates the issue as network-reachable with low attack complexity and no privileges or user interaction required. The vulnerable nftables rule configuration must already be present for the transmit-path evaluation to occur.

4

What can be done before an update is available?

Audit netdev egress base chains for FIB expressions and remove or relocate unsupported uses. Input-device cases, including OIF, OIFNAME, and ADDRTYPE with F_IIF, should be limited to ingress; ADDRTYPE with F_OIF is intended for egress, while ADDRTYPE without a device flag can be used on either hook.

Company

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