UBUNTU-CVE-2026-74705: Use After Free

Published Aug 22, 2026
·
Updated

In the Linux kernel, the following vulnerability has been resolved: udp: fix potential use-after-free in tunnel segmentation skbudptunnelsegment() gets the UDP header before ensuring the tunnel header is in the skb head. If the pull reallocates skb->head, the saved UDP header pointer is no longer valid. Get the UDP header after the pull to avoid a potential use-after-free.

Affected Software

246 affected componentsFixes available
ubuntu/linux-azure*
ubuntu/linux-aws-hwe*
ubuntu/linux-azure*
ubuntu/linux-gcp*
ubuntu/linux-hwe*
ubuntu/linux-hwe-edge*
ubuntu/linux-oracle*
ubuntu/linux*
ubuntu/linux-aws*
ubuntu/linux-aws-5.0*
ubuntu/linux-aws-5.3*
ubuntu/linux-aws-5.4*
ubuntu/linux-azure*
ubuntu/linux-azure-4.15*
ubuntu/linux-azure-5.3*
ubuntu/linux-azure-5.4*
ubuntu/linux-azure-edge*
ubuntu/linux-gcp*
ubuntu/linux-gcp-4.15*
ubuntu/linux-gcp-5.3*
ubuntu/linux-gcp-5.4*
ubuntu/linux-gke-4.15*
ubuntu/linux-gke-5.4*
ubuntu/linux-gkeop-5.4*
ubuntu/linux-hwe*
ubuntu/linux-hwe-5.4*
ubuntu/linux-hwe-edge*
ubuntu/linux-ibm-5.4*
ubuntu/linux-kvm*
ubuntu/linux-oem*
ubuntu/linux-oracle*
ubuntu/linux-oracle-5.0*
ubuntu/linux-oracle-5.3*
ubuntu/linux-oracle-5.4*
ubuntu/linux-raspi-5.4*
ubuntu/linux-aws-fips*
ubuntu/linux-azure-fips*
ubuntu/linux-fips*
ubuntu/linux-gcp-fips*
ubuntu/linux-aws-fips*
ubuntu/linux-azure-fips*
ubuntu/linux-fips*
ubuntu/linux-gcp-fips*
ubuntu/linux*
ubuntu/linux-aws*
ubuntu/linux-aws-5.11*
ubuntu/linux-aws-5.13*
ubuntu/linux-aws-5.15<5.15.0-1117.124~20.04.1
5.15.0-1117.124~20.04.1
ubuntu/linux-aws-5.8*
ubuntu/linux-azure*
ubuntu/linux-azure-5.11*
ubuntu/linux-azure-5.13*
ubuntu/linux-azure-5.15<5.15.0-1123.132~20.04.1
5.15.0-1123.132~20.04.1
ubuntu/linux-azure-5.8*
ubuntu/linux-azure-fde*
ubuntu/linux-azure-fde-5.15<5.15.0-1122.131~20.04.1
5.15.0-1122.131~20.04.1
ubuntu/linux-bluefield*
ubuntu/linux-gcp*
ubuntu/linux-gcp-5.11*
ubuntu/linux-gcp-5.13*
ubuntu/linux-gcp-5.15<5.15.0-1118.128~20.04.1
5.15.0-1118.128~20.04.1
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-5.15<5.15.0-198.208~20.04.1
5.15.0-198.208~20.04.1
ubuntu/linux-hwe-5.8*
ubuntu/linux-ibm*
ubuntu/linux-ibm-5.15<5.15.0-1111.115~20.04.1
5.15.0-1111.115~20.04.1
ubuntu/linux-intel-5.13*
ubuntu/linux-intel-iotg-5.15<5.15.0-1112.118~20.04.1
5.15.0-1112.118~20.04.1
ubuntu/linux-iot*
ubuntu/linux-kvm*
ubuntu/linux-lowlatency-hwe-5.15<5.15.0-195.205~20.04.1
5.15.0-195.205~20.04.1
ubuntu/linux-nvidia-tegra-5.15*
ubuntu/linux-oem-5.10*
ubuntu/linux-oem-5.13*
ubuntu/linux-oem-5.6*
ubuntu/linux-oracle*
ubuntu/linux-oracle-5.11*
ubuntu/linux-oracle-5.13*
ubuntu/linux-oracle-5.15<5.15.0-1114.120~20.04.1
5.15.0-1114.120~20.04.1
ubuntu/linux-oracle-5.8*
ubuntu/linux-raspi*
ubuntu/linux-raspi2*
ubuntu/linux-riscv*
ubuntu/linux-riscv-5.11*
ubuntu/linux-riscv-5.15<5.15.0-1111.115~20.04.1
5.15.0-1111.115~20.04.1
ubuntu/linux-riscv-5.8*
ubuntu/linux-xilinx-zynqmp*
ubuntu/linux-aws-fips*
ubuntu/linux-azure-fips*
ubuntu/linux-fips*
ubuntu/linux-gcp-fips*
ubuntu/linux-aws-fips*
ubuntu/linux-azure-fips*
ubuntu/linux-fips*
ubuntu/linux-gcp-fips*
ubuntu/linux<5.15.0-198.208
5.15.0-198.208
ubuntu/linux-allwinner-5.19*
ubuntu/linux-aws<5.15.0-1117.124
5.15.0-1117.124
ubuntu/linux-aws-5.19*
ubuntu/linux-aws-6.2*
ubuntu/linux-aws-6.5*
ubuntu/linux-aws-6.8*
ubuntu/linux-azure<5.15.0-1123.132
5.15.0-1123.132
ubuntu/linux-azure-5.19*
ubuntu/linux-azure-6.2*
ubuntu/linux-azure-6.5*
ubuntu/linux-azure-6.8*
ubuntu/linux-azure-fde<5.15.0-1122.131
5.15.0-1122.131
ubuntu/linux-azure-fde-5.19*
ubuntu/linux-azure-fde-6.2*
ubuntu/linux-azure-fde-6.8*
ubuntu/linux-gcp<5.15.0-1118.128
5.15.0-1118.128
ubuntu/linux-gcp-5.19*
ubuntu/linux-gcp-6.2*
ubuntu/linux-gcp-6.5*
ubuntu/linux-gcp-6.8*
ubuntu/linux-gke<5.15.0-1113.119
5.15.0-1113.119
ubuntu/linux-gkeop<5.15.0-1100.108
5.15.0-1100.108
ubuntu/linux-hwe-5.19*
ubuntu/linux-hwe-6.2*
ubuntu/linux-hwe-6.5*
ubuntu/linux-ibm<5.15.0-1111.115
5.15.0-1111.115
ubuntu/linux-ibm-6.8*
ubuntu/linux-intel-iot-realtime*
ubuntu/linux-intel-iotg<5.15.0-1112.118
5.15.0-1112.118
ubuntu/linux-kvm<5.15.0-1109.114
5.15.0-1109.114
ubuntu/linux-lowlatency<5.15.0-195.205
5.15.0-195.205
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<5.15.0-1112.113
5.15.0-1112.113
ubuntu/linux-nvidia-6.2*
ubuntu/linux-nvidia-6.5*
ubuntu/linux-nvidia-6.8*
ubuntu/linux-nvidia-tegra*
ubuntu/linux-nvidia-tegra-igx*
ubuntu/linux-oem-5.17*
ubuntu/linux-oem-6.0*
ubuntu/linux-oem-6.1*
ubuntu/linux-oem-6.5*
ubuntu/linux-oracle<5.15.0-1114.120
5.15.0-1114.120
ubuntu/linux-oracle-6.5*
ubuntu/linux-oracle-6.8*
ubuntu/linux-raspi*
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-xilinx-zynqmp<5.15.0-1080.84
5.15.0-1080.84
ubuntu/linux-bluefield<5.15.0-1101.103
5.15.0-1101.103
ubuntu/linux-intel-iot-realtime<5.15.0-1109.111
5.15.0-1109.111
ubuntu/linux-realtime<5.15.0-1116.125
5.15.0-1116.125
ubuntu/linux-realtime-6.8*
ubuntu/linux-aws-fips*
ubuntu/linux-azure-fips*
ubuntu/linux-fips*
ubuntu/linux-gcp-fips*
ubuntu/linux-aws-fips<5.15.0-1117.124+fips1
5.15.0-1117.124+fips1
ubuntu/linux-azure-fips<5.15.0-1123.132+fips1
5.15.0-1123.132+fips1
ubuntu/linux-fips<5.15.0-198.208+fips1
5.15.0-198.208+fips1
ubuntu/linux-gcp-fips<5.15.0-1118.128+fips1
5.15.0-1118.128+fips1
ubuntu/linux*
ubuntu/linux-aws*
ubuntu/linux-aws-6.14*
ubuntu/linux-aws-6.17*
ubuntu/linux-aws-7.0*
ubuntu/linux-azure*
ubuntu/linux-azure-6.11*
ubuntu/linux-azure-6.14*
ubuntu/linux-azure-6.17*
ubuntu/linux-azure-7.0*
ubuntu/linux-azure-fde*
ubuntu/linux-azure-fde-6.14*
ubuntu/linux-azure-fde-6.17*
ubuntu/linux-azure-fde-7.0*
ubuntu/linux-azure-nvidia*
ubuntu/linux-azure-nvidia-6.14*
ubuntu/linux-gcp*
ubuntu/linux-gcp-6.11*
ubuntu/linux-gcp-6.14*
ubuntu/linux-gcp-7.0*
ubuntu/linux-gke*
ubuntu/linux-gkeop*
ubuntu/linux-hwe-6.11*
ubuntu/linux-hwe-6.14*
ubuntu/linux-hwe-6.17*
ubuntu/linux-hwe-7.0*
ubuntu/linux-ibm*
ubuntu/linux-lowlatency*
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*
ubuntu/linux-oracle-6.14*
ubuntu/linux-oracle-6.17*
ubuntu/linux-oracle-7.0*
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*
ubuntu/linux-xilinx*
ubuntu/linux-bluefield*
ubuntu/linux-raspi-realtime*
ubuntu/linux-realtime*
ubuntu/linux-realtime-6.14*
ubuntu/linux-realtime-6.17*
ubuntu/linux-aws-fips*
ubuntu/linux-azure-fips*
ubuntu/linux-fips*
ubuntu/linux-gcp-fips*
ubuntu/linux*
ubuntu/linux-aws*
ubuntu/linux-azure*
ubuntu/linux-azure-fde*
ubuntu/linux-gcp*
ubuntu/linux-gke*
ubuntu/linux-ibm*
ubuntu/linux-nvidia*
ubuntu/linux-nvidia-bos*
ubuntu/linux-oem-7.0*
ubuntu/linux-oracle*
ubuntu/linux-raspi*
ubuntu/linux-realtime*
ubuntu/linux-riscv*

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade ubuntu/linux-aws-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1117.124~20.04.1
  2. Upgrade

    Upgrade ubuntu/linux-azure-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1123.132~20.04.1
  3. Upgrade

    Upgrade ubuntu/linux-azure-fde-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1122.131~20.04.1
  4. Upgrade

    Upgrade ubuntu/linux-gcp-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1118.128~20.04.1
  5. Upgrade

    Upgrade ubuntu/linux-hwe-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-198.208~20.04.1
  6. Upgrade

    Upgrade ubuntu/linux-ibm-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1111.115~20.04.1
  7. Upgrade

    Upgrade ubuntu/linux-intel-iotg-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1112.118~20.04.1
  8. Upgrade

    Upgrade ubuntu/linux-lowlatency-hwe-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-195.205~20.04.1
  9. Upgrade

    Upgrade ubuntu/linux-oracle-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1114.120~20.04.1
  10. Upgrade

    Upgrade ubuntu/linux-riscv-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1111.115~20.04.1
  11. Upgrade

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

    Fixed in 5.15.0-198.208
  12. Upgrade

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

    Fixed in 5.15.0-1117.124
  13. Upgrade

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

    Fixed in 5.15.0-1123.132
  14. Upgrade

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

    Fixed in 5.15.0-1122.131
  15. Upgrade

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

    Fixed in 5.15.0-1118.128
  16. Upgrade

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

    Fixed in 5.15.0-1113.119
  17. Upgrade

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

    Fixed in 5.15.0-1100.108
  18. Upgrade

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

    Fixed in 5.15.0-1111.115
  19. Upgrade

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

    Fixed in 5.15.0-1112.118
  20. Upgrade

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

    Fixed in 5.15.0-1109.114
  21. Upgrade

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

    Fixed in 5.15.0-195.205
  22. Upgrade

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

    Fixed in 5.15.0-1112.113
  23. Upgrade

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

    Fixed in 5.15.0-1114.120
  24. Upgrade

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

    Fixed in 5.15.0-1080.84
  25. Upgrade

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

    Fixed in 5.15.0-1101.103
  26. Upgrade

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

    Fixed in 5.15.0-1109.111
  27. Upgrade

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

    Fixed in 5.15.0-1116.125
  28. Upgrade

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

    Fixed in 5.15.0-1117.124+fips1
  29. Upgrade

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

    Fixed in 5.15.0-1123.132+fips1
  30. Upgrade

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

    Fixed in 5.15.0-198.208+fips1
  31. Upgrade

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

    Fixed in 5.15.0-1118.128+fips1
  32. Upgrade

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

    Fixed in 6.8.0-1036.39
  33. Compensating control

    In __skb_udp_tunnel_segment(), ensure the tunnel header is in the skb head before obtaining the UDP header; retrieve the UDP header after the pull so a possible skb->head reallocation cannot leave a stale pointer.

Event History

Aug 22, 2026
CVE Published
via OSV·04:16 PM
Data Sourced
via OSV·04:16 PM
DescriptionSeverityAffected Software

Frequently Asked Questions

1

What level of access does an attacker need to exploit this issue?

The severity vector indicates network exploitation with low attack complexity. It does not require privileges or user interaction.

2

What could successful exploitation allow?

The severity vector rates confidentiality, integrity, and availability impact as high. It also indicates the vulnerability can affect components beyond the vulnerable security authority.

3

Which Ubuntu kernel package families are listed as affected?

The listed packages are linux, linux-azure, linux-azure-fips, linux-aws-fips, linux-fips, linux-gcp, linux-gcp-fips, and linux-oracle.

Company

Resources

Contact

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