CVE-2026-72248: netfilter: flowtable: support IPIP tunnel with direct xmit

Q: What is the severity of CVE-2026-72248?

The severity of CVE-2026-72248 is rated at 27.

Q: How do I fix CVE-2026-72248?

To fix CVE-2026-72248, you need to update the Linux kernel to a version that has resolved this vulnerability.

Q: What systems are affected by CVE-2026-72248?

CVE-2026-72248 affects systems running vulnerable versions of the Linux kernel with support for IPIP tunnels.

Q: What impact does CVE-2026-72248 have on network functionality?

CVE-2026-72248 can disrupt network operations by causing issues with IPIP tunnels that utilize direct xmit on bridge devices.

Q: Is CVE-2026-72248 a remote or local exploit?

CVE-2026-72248 is primarily a local exploit related to specific network configurations, but can affect network communication.

Published Aug 15, 2026

Updated

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

netfilter: flowtable: support IPIP tunnel with direct xmit

The combination of IPIP tunnel with direct xmit, eg. bridge device, breaks because no dstentry is provided to check the skb headroom and to set the iph->fragoff field. This leads to invalid dst usage and can trigger a crash in the tunnel transmit path.

Fix this by moving dstcache and dstcookie out of the runtime union so that they can be shared by neighbour, xfrm, and direct tunnel flows. For FLOWOFFLOADXMITDIRECT tuples carrying tunnel metadata, preserve route state in these shared fields and release it through the common dst release path.

Since dstentry is now available to the three supported xmit modes and dstrelease() already deals with NULL dst, remove the xmit type check in nftflowdstrelease(). Moreover, skip the check if the dst entry is NULL in nfflowdstcheck() which is now the case for the direct xmit case.

Based on patch from Rein Wei <n05ec@lzu.edu.cn>.

Affected Software

126 affected componentsFixes available

Linux Linux kernel

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-azure-5.19*

ubuntu/linux-azure-6.2*

ubuntu/linux-azure-6.5*

ubuntu/linux-azure-fde-5.19*

ubuntu/linux-azure-fde-6.2*

ubuntu/linux-gcp-5.19*

ubuntu/linux-gcp-6.2*

ubuntu/linux-gcp-6.5*

ubuntu/linux-hwe-5.19*

ubuntu/linux-hwe-6.2*

ubuntu/linux-hwe-6.5*

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-nvidia-6.2*

ubuntu/linux-nvidia-6.5*

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-realtime*

ubuntu/linux-riscv*

ubuntu/linux-riscv-5.19*

ubuntu/linux-riscv-6.5*

ubuntu/linux-starfive-5.19*

ubuntu/linux-starfive-6.2*

ubuntu/linux-starfive-6.5*

ubuntu/linux-aws-6.14*

ubuntu/linux-aws-6.17*

ubuntu/linux-aws-7.0<7.0.0-1013.13~24.04.1

7.0.0-1013.13~24.04.1

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-6.14*

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-6.14*

ubuntu/linux-gcp-6.11*

ubuntu/linux-gcp-6.14*

ubuntu/linux-gcp-7.0<7.0.0-1013.13~24.04.1

7.0.0-1013.13~24.04.1

ubuntu/linux-hwe-6.11*

ubuntu/linux-hwe-6.14*

ubuntu/linux-hwe-7.0<7.0.0-34.34~24.04.1

7.0.0-34.34~24.04.1

ubuntu/linux-lowlatency-hwe-6.11*

ubuntu/linux-nvidia-6.11*

ubuntu/linux-nvidia-7.0<7.0.0-1024.25~24.04.1

7.0.0-1024.25~24.04.1

ubuntu/linux-oem-6.11*

ubuntu/linux-oem-6.14*

ubuntu/linux-oem-6.8*

ubuntu/linux-oracle-6.14*

ubuntu/linux-oracle-7.0<7.0.0-1012.12~24.04.1

7.0.0-1012.12~24.04.1

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<7.0.0-34.34.1~24.04.1

7.0.0-34.34.1~24.04.1

ubuntu/linux-realtime-6.14*

ubuntu/linux-realtime-6.17*

ubuntu/linux<7.0.0-34.34

7.0.0-34.34

ubuntu/linux-aws<7.0.0-1013.13

7.0.0-1013.13

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<7.0.0-1013.13

7.0.0-1013.13

ubuntu/linux-gke<7.0.0-1007.8

7.0.0-1007.8

ubuntu/linux-ibm<7.0.0-1014.14

7.0.0-1014.14

ubuntu/linux-nvidia*

ubuntu/linux-nvidia-bos<7.0.0-2022.23

7.0.0-2022.23

ubuntu/linux-oem-7.0<7.0.0-1014.14

7.0.0-1014.14

ubuntu/linux-oracle<7.0.0-1012.12

7.0.0-1012.12

ubuntu/linux-raspi<7.0.0-1020.20

7.0.0-1020.20

ubuntu/linux-realtime<7.0.0-34.34.1

7.0.0-34.34.1

ubuntu/linux-riscv<7.0.0-34.34.1

7.0.0-34.34.1

ubuntu/linux-vmware*

Remediation

Recommended actions to resolve this vulnerability, in priority order.

Upgrade
Upgrade ubuntu/linux-aws-7.0 to a version that resolves this vulnerability.
Fixed in 7.0.0-1013.13~24.04.1
Upgrade
Upgrade ubuntu/linux-azure-7.0 to a version that resolves this vulnerability.
Fixed in 7.0.0-1017.17~24.04.1
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
Upgrade
Upgrade ubuntu/linux-gcp-7.0 to a version that resolves this vulnerability.
Fixed in 7.0.0-1013.13~24.04.1
Upgrade
Upgrade ubuntu/linux-hwe-7.0 to a version that resolves this vulnerability.
Fixed in 7.0.0-34.34~24.04.1
Upgrade
Upgrade ubuntu/linux-nvidia-7.0 to a version that resolves this vulnerability.
Fixed in 7.0.0-1024.25~24.04.1
Upgrade
Upgrade ubuntu/linux-oracle-7.0 to a version that resolves this vulnerability.
Fixed in 7.0.0-1012.12~24.04.1
Upgrade
Upgrade ubuntu/linux-riscv-7.0 to a version that resolves this vulnerability.
Fixed in 7.0.0-34.34.1~24.04.1
Upgrade
Upgrade ubuntu/linux to a version that resolves this vulnerability.
Fixed in 7.0.0-34.34
Upgrade
Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.
Fixed in 7.0.0-1013.13
Upgrade
Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.
Fixed in 7.0.0-1017.17
Upgrade
Upgrade ubuntu/linux-azure-fde to a version that resolves this vulnerability.
Fixed in 7.0.0-1016.16
Upgrade
Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.
Fixed in 7.0.0-1013.13
Upgrade
Upgrade ubuntu/linux-gke to a version that resolves this vulnerability.
Fixed in 7.0.0-1007.8
Upgrade
Upgrade ubuntu/linux-ibm to a version that resolves this vulnerability.
Fixed in 7.0.0-1014.14
Upgrade
Upgrade ubuntu/linux-nvidia-bos to a version that resolves this vulnerability.
Fixed in 7.0.0-2022.23
Upgrade
Upgrade ubuntu/linux-oem-7.0 to a version that resolves this vulnerability.
Fixed in 7.0.0-1014.14
Upgrade
Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.
Fixed in 7.0.0-1012.12
Upgrade
Upgrade ubuntu/linux-raspi to a version that resolves this vulnerability.
Fixed in 7.0.0-1020.20
Upgrade
Upgrade ubuntu/linux-realtime to a version that resolves this vulnerability.
Fixed in 7.0.0-34.34.1
Upgrade
Upgrade ubuntu/linux-riscv to a version that resolves this vulnerability.
Fixed in 7.0.0-34.34.1

Event History

Aug 15, 2026

CVE Published

via MITRE·05:54 AM

Data Sourced

via MITRE·05:54 AM

DescriptionSeverity

Data Sourced

via OSV·06:21 AM

DescriptionSeverityAffected Software

Data Sourced

via NVD·06:21 AM

DescriptionSeverity

Frequently Asked Questions

What is the severity of CVE-2026-72248?

The severity of CVE-2026-72248 is rated at 27.

How do I fix CVE-2026-72248?

To fix CVE-2026-72248, you need to update the Linux kernel to a version that has resolved this vulnerability.

What systems are affected by CVE-2026-72248?

CVE-2026-72248 affects systems running vulnerable versions of the Linux kernel with support for IPIP tunnels.

What impact does CVE-2026-72248 have on network functionality?

CVE-2026-72248 can disrupt network operations by causing issues with IPIP tunnels that utilize direct xmit on bridge devices.

Is CVE-2026-72248 a remote or local exploit?

CVE-2026-72248 is primarily a local exploit related to specific network configurations, but can affect network communication.

CVE-2026-72248: netfilter: flowtable: support IPIP tunnel with direct xmit

Affected Software

Remediation

Event History

Frequently Asked Questions

What is the severity of CVE-2026-72248?

How do I fix CVE-2026-72248?

What systems are affected by CVE-2026-72248?

What impact does CVE-2026-72248 have on network functionality?

Is CVE-2026-72248 a remote or local exploit?

Company

Resources

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