CVE-2026-64566: xfrm: iptfs: propagate SKBFL_SHARED_FRAG in iptfs_skb_add_frags()

Published Aug 5, 2026

Updated

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

xfrm: iptfs: propagate SKBFLSHAREDFRAG in iptfsskbaddfrags()

When iptfsskbaddfrags() copies frag references from the source frag walk into a new SKB, it increments the page reference count via skbfragref() but does not propagate SKBFLSHAREDFRAG to the destination SKB's skbshinfo->flags.

If the source SKB carries shared frags (e.g. from a page-pool backed receive path), the new inner SKB will appear to ESP as having privately owned frags. A subsequent espinput() call for a nested transport-mode SA then takes the no-COW fast path and decrypts in place, writing over pages that are still referenced by the outer IPTFS SKB. This causes kernel-visible memory corruption and can trigger a panic.

All other frag-transfer helpers in the kernel (skbtrycoalesce, skbgroreceive, pskbcopyfclone, skbshift, skbsegment) correctly propagate SKBFLSHAREDFRAG; align iptfsskbaddfrags() with this convention by setting the flag inside the loop immediately after skbfragref() and nrfrags++, so every exit path that attaches a frag unconditionally propagates SKBFLSHAREDFRAG.

Affected Software

131 affected componentsFixes available

Linux Linux kernel

debian/linux<7.1.6-1

7.1.6-1

debian/linux

6.1.176-16.1.190-16.12.107-16.12.115-27.2.12-17.2.15-1

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<7.0.0-1014.14~24.04.1

7.0.0-1014.14~24.04.1

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-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<7.0.0-1014.14~24.04.1

7.0.0-1014.14~24.04.1

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-lowlatency-hwe-6.11*

ubuntu/linux-nvidia-6.11*

ubuntu/linux-nvidia-6.17*

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-6.17*

ubuntu/linux-oem-6.8*

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-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-realtime-6.14*

ubuntu/linux-realtime-6.17*

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<7.0.0-2022.23

7.0.0-2022.23

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

ubuntu/linux-vmware*

Remediation

Recommended actions to resolve this vulnerability, in priority order.

Upgrade
Upgrade debian/linux to a version that resolves this vulnerability.
Fixed in 7.1.6-1
Upgrade
Upgrade debian/linux to a version that resolves this vulnerability.
Fixed in 6.1.176-1Fixed in 6.1.190-1Fixed in 6.12.107-1Fixed in 6.12.115-2Fixed in 7.2.12-1Fixed in 7.2.15-1
Upgrade
Upgrade ubuntu/linux-aws-7.0 to a version that resolves this vulnerability.
Fixed in 7.0.0-1014.14~24.04.1
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 7.0.0-1014.14~24.04.1
Upgrade
Upgrade ubuntu/linux-hwe-7.0 to a version that resolves this vulnerability.
Fixed in 7.0.0-38.38~24.04.4
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 7.0.0-1013.13~24.04.1
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
Upgrade
Upgrade ubuntu/linux to a version that resolves this vulnerability.
Fixed in 7.0.0-38.38
Upgrade
Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.
Fixed in 7.0.0-1014.14
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 7.0.0-1014.14
Upgrade
Upgrade ubuntu/linux-gke to a version that resolves this vulnerability.
Fixed in 7.0.0-1008.9
Upgrade
Upgrade ubuntu/linux-ibm to a version that resolves this vulnerability.
Fixed in 7.0.0-1015.15
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 7.0.0-1015.15
Upgrade
Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.
Fixed in 7.0.0-1013.13
Upgrade
Upgrade ubuntu/linux-realtime to a version that resolves this vulnerability.
Fixed in 7.0.0-38.38.1
Upgrade
Upgrade ubuntu/linux-riscv to a version that resolves this vulnerability.
Fixed in 7.0.0-38.38.1
Compensating control
In iptfs_skb_add_frags(), set SKBFL_SHARED_FRAG in the destination SKB's skb_shinfo->flags inside the fragment-copy loop immediately after __skb_frag_ref() and nr_frags++, so every attached fragment propagates the shared-fragment flag.

Event History

Aug 5, 2026

CVE Published

via MITRE·08:06 AM

Data Sourced

via MITRE·08:06 AM

DescriptionSeverity

Data Sourced

via OSV·08:16 AM

DescriptionSeverityAffected Software

Event

via OSV·08:16 AM

Data Sourced

via NVD·08:16 AM

DescriptionSeverity

Frequently Asked Questions

What is the severity of CVE-2026-64566?

CVE-2026-64566 has a risk rating of 57.

What systems are affected by CVE-2026-64566?

CVE-2026-64566 affects the Linux kernel.

How do I fix CVE-2026-64566?

To fix CVE-2026-64566, you should update your Linux kernel to the latest patched version provided by your distribution.

What are the potential impacts of CVE-2026-64566?

The potential impact of CVE-2026-64566 is related to improper handling of SKB fragment references, which may lead to memory management issues.

When was CVE-2026-64566 published?

CVE-2026-64566 was published on August 5, 2026.

CVE-2026-64566: xfrm: iptfs: propagate SKBFL_SHARED_FRAG in iptfs_skb_add_frags()

Affected Software

Remediation

Event History

Frequently Asked Questions

What is the severity of CVE-2026-64566?

What systems are affected by CVE-2026-64566?

How do I fix CVE-2026-64566?

What are the potential impacts of CVE-2026-64566?

When was CVE-2026-64566 published?

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