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Vulnerability · Published Sep 11, 2026 · Assigned by Linux

CVE-2026-80978net: cap advertised IP tunnel headroom

High 7.8

In plain English

A high-severity security flaw in Linux from Linux. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 3% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.8High
Exploit odds (30 days)0.1%top 97.4% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

In the Linux kernel, the following vulnerability has been resolved: net: cap advertised IP tunnel headroom IP tunnel devices derive their advertised needed_headroom from lower output devices. A stack of user-created devices can make the derived value larger than the 16-bit skb header offsets can represent. Once IP output reserves it, skb head expansion can wrap those offsets. The runtime transmit path already caps a growing needed_headroom at 512. Apply the same cap when tunnel configuration publishes needed_headroom derived from a lower output device. Capping the advertised value is safe: IP tunnel transmit still expands the skb when a packet needs more headroom. A nonsensical stacked configuration can therefore incur an extra reallocation, but it cannot publish an unbounded reservation to upper layers.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12linux6.1.190-1DEBIAN-CVE-2026-80978
Debian:13linux6.12.111-1DEBIAN-CVE-2026-80978
Debian:14linux7.2.6-1DEBIAN-CVE-2026-80978
Debian:12linux-6.126.12.111-1~deb12u1DEBIAN-CVE-2026-80978
Ubuntu:22.04:LTSlinux5.15.0-202.212UBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinuxno fix listedUBUNTU-CVE-2026-80978
Ubuntu:26.04:LTSlinux7.0.0-42.42UBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-aws5.15.0-1119.126UBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-awsno fix listedUBUNTU-CVE-2026-80978
Ubuntu:26.04:LTSlinux-aws7.0.0-1016.17UBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-aws-6.14no fix listedUBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-aws-6.17no fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-aws-6.8no fix listedUBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-aws-7.0no fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-azure5.15.0-1125.134UBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-azureno fix listedUBUNTU-CVE-2026-80978
Ubuntu:26.04:LTSlinux-azureno fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-azure-6.11no fix listedUBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-azure-6.14no fix listedUBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-azure-6.17no fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-azure-6.8no fix listedUBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-azure-7.0no fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-azure-fde5.15.0-1124.133UBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-azure-fdeno fix listedUBUNTU-CVE-2026-80978
Ubuntu:26.04:LTSlinux-azure-fdeno fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-azure-fde-6.14no fix listedUBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-azure-fde-6.17no fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-azure-fde-6.8no fix listedUBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-azure-fde-7.0no fix listedUBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-azure-nvidiano fix listedUBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-azure-nvidia-6.14no fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-gcp5.15.0-1120.130UBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-gcpno fix listedUBUNTU-CVE-2026-80978
Ubuntu:26.04:LTSlinux-gcp7.0.0-1016.18UBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-gcp-6.11no fix listedUBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-gcp-6.14no fix listedUBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-gcp-6.17no fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-gcp-6.8no fix listedUBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-gcp-7.0no fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-gke5.15.0-1115.121UBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-gkeno fix listedUBUNTU-CVE-2026-80978
Ubuntu:26.04:LTSlinux-gkeno fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-gkeop5.15.0-1102.110UBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-gkeopno fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-hwe-6.11no fix listedUBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-hwe-6.14no fix listedUBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-hwe-6.17no fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-hwe-6.8no fix listedUBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-hwe-7.07.0.0-42.42~24.04.1UBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-ibm5.15.0-1113.117UBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-ibmno fix listedUBUNTU-CVE-2026-80978
Ubuntu:26.04:LTSlinux-ibm7.0.0-1017.17UBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-ibm-6.8no fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-intel-iotg5.15.0-1114.120UBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-kvm5.15.0-1111.116UBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-lowlatency5.15.0-197.207UBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-lowlatencyno fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.11no fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.8no fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-nvidia5.15.0-1114.115UBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-nvidiano fix listedUBUNTU-CVE-2026-80978
Ubuntu:26.04:LTSlinux-nvidiano fix listedUBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-nvidia-6.11no fix listedUBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-nvidia-6.17no fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-nvidia-6.8no fix listedUBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-nvidia-7.0no fix listedUBUNTU-CVE-2026-80978
Ubuntu:26.04:LTSlinux-nvidia-bosno fix listedUBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-nvidia-lowlatencyno fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-nvidia-tegra5.15.0-1070.72UBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-nvidia-tegra6.8.0-1038.42UBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-nvidia-tegra-igx5.15.0-1059.59UBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-oem-6.11no fix listedUBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-oem-6.14no fix listedUBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-oem-6.17no fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-oem-6.8no fix listedUBUNTU-CVE-2026-80978
Ubuntu:26.04:LTSlinux-oem-7.07.0.0-1017.17UBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-oracle5.15.0-1116.122UBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-oracleno fix listedUBUNTU-CVE-2026-80978
Ubuntu:26.04:LTSlinux-oracle7.0.0-1015.16UBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-oracle-6.14no fix listedUBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-oracle-6.17no fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-oracle-6.8no fix listedUBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-oracle-7.0no fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-raspino fix listedUBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-raspino fix listedUBUNTU-CVE-2026-80978
Ubuntu:26.04:LTSlinux-raspino fix listedUBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-80978
Ubuntu:26.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-80978
Ubuntu:26.04:LTSlinux-riscv7.0.0-42.42.1UBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-riscv-6.14no fix listedUBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-riscv-6.17no fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-riscv-6.8no fix listedUBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-riscv-7.07.0.0-42.42.1~24.04.1UBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-vmwareno fix listedUBUNTU-CVE-2026-80978
Ubuntu:24.04:LTSlinux-xilinxno fix listedUBUNTU-CVE-2026-80978
Ubuntu:22.04:LTSlinux-xilinx-zynqmpno fix listedUBUNTU-CVE-2026-80978

Affected products (as reported)

VendorProductVersions
Linux Linux 1a37e412a0225fcba5587f24c0dfc7636efc8b69 – before fb889a619723032140f5d983a3a34d25a5a2bed41a37e412a0225fcba5587f24c0dfc7636efc8b69 – before b160422f8103574425e2834130e169d84c94fa1d1a37e412a0225fcba5587f24c0dfc7636efc8b69 – before d36e75f5669140b66515ad3a176ca6337bd80a5e1a37e412a0225fcba5587f24c0dfc7636efc8b69 – before 84783961cb8bdb36b4f41a02ce43aafc6d52b1761a37e412a0225fcba5587f24c0dfc7636efc8b69 – before bc4e05ae66c9797a0972ac44326e69c5305e00201a37e412a0225fcba5587f24c0dfc7636efc8b69 – before af0ee8f04bea22cdb331fa3509e17f81b48938ad1a37e412a0225fcba5587f24c0dfc7636efc8b69 – before 9144f2c53a04465a6878172b523f640313c5559e1a37e412a0225fcba5587f24c0dfc7636efc8b69 – before 6b222adeb9340306e2ff97127c76117abb9b3df8
Linux Linux 3.11

References