In the Linux kernel, the following vulnerability has been resolved:
tun: zero the whole vnet header in tun_put_user()
tun_put_user() declares an on-stack struct virtio_net_hdr_v1_hash_tunnel without zeroing it. For a non-tunnel skb, virtio_net_hdr_tnl_from_skb() only initializes the first 10 bytes (sizeof(struct virtio_net_hdr)), leaving bytes 10..23 (num_buffers and the hash/tunnel fields) as stack garbage.
An unprivileged user can set the vnet header size to 24 with TUNSETVNETHDRSZ, so __tun_vnet_hdr_put() copies all 24 bytes of the partially-initialized struct to userspace, leaking 14 bytes of kernel stack on every read of a non-tunnel packet.
Fix it the same way tun_get_user() already does by zeroing the whole header right after declaration.
CVSS Details
- CVSS 3.1 Base Score: 5.5
- CVSS 3.1 Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Amazon_linux_2023 | — | Upgrade perf6.18Upgrade kernel6.18-develUpgrade bpftool6.18Upgrade kernel6.18-debuginfo-common-x86_64Upgrade kernel6.18-tools-develUpgrade python3-perf6.18Upgrade microvm-kernel6.18Upgrade kernel6.18-modules-extra-commonUpgrade kernel6.18Upgrade python3-perf6.18-debuginfoUpgrade kernel-livepatch-6.18.36-69.134Upgrade kernel6.18-debuginfoUpgrade kernel6.18-headersUpgrade perf6.18-debuginfoUpgrade kernel6.18-tools-debuginfoUpgrade kernel6.18-modules-extraUpgrade kernel6.18-debuginfo-common-aarch64Upgrade bpftool6.18-debuginfoUpgrade kernel6.18-tools | Jul 21, 2026 | Jun 24, 2026 |
| Redhat_linux | — | No solution exists | Jul 17, 2026 | Jun 24, 2026 |
| Ubuntu | — | Upgrade linux-image-gcpUpgrade linux-image-gcp-7.0Upgrade linux-image-oracle-7.0Upgrade linux-image-7.0.0-31-realtimeUpgrade linux-image-oem-26.04bUpgrade linux-image-oracle-64k-7.0Upgrade linux-image-aws-64kUpgrade linux-image-nvidiaUpgrade linux-image-oem-26.04Upgrade linux-image-7.0.0-1011-gcpUpgrade linux-image-ibm-7.0Upgrade linux-image-nvidia-64k-7.0Upgrade linux-image-azure-lts-26.04Upgrade linux-image-7.0.0-1011-gcp-64kUpgrade linux-image-7.0.0-1018-nvidiaUpgrade linux-image-virtual-hwe-24.04Upgrade linux-image-7.0.0-1011-oracleUpgrade linux-image-generic-64k-7.0Upgrade linux-image-oracleUpgrade linux-image-7.0.0-2018-nvidia-bos-64kUpgrade linux-image-7.0.0-31-realtime-64kUpgrade linux-image-virtual-7.0Upgrade linux-image-nvidia-bos-64k-7.0Upgrade linux-image-ibmUpgrade linux-image-virtualUpgrade linux-image-7.0.0-1013-ibmUpgrade linux-image-7.0.0-1006-gke-64kUpgrade linux-image-generic-64k-hwe-24.04Upgrade linux-image-7.0.0-31-genericUpgrade linux-image-7.0.0-1012-aws-64kUpgrade linux-image-nvidia-bos-7.0Upgrade linux-image-7.0.0-1006-gkeUpgrade linux-image-generic-64kUpgrade linux-image-genericUpgrade linux-image-raspi-realtimeUpgrade linux-image-virtual-hwe-26.04Upgrade linux-image-gkeUpgrade linux-image-azureUpgrade linux-image-generic-7.0Upgrade linux-image-azure-7.0Upgrade linux-image-realtime-64k-hwe-26.04Upgrade linux-image-raspi-7.0Upgrade linux-image-realtime-7.0Upgrade linux-image-nvidia-hwe-26.04Upgrade linux-image-generic-64k-hwe-26.04Upgrade linux-image-awsUpgrade linux-image-7.0.0-31-generic-64kUpgrade linux-image-gke-64k-hwe-26.04Upgrade linux-image-gke-7.0Upgrade linux-image-gke-64k-7.0Upgrade linux-image-generic-hwe-26.04Upgrade linux-image-7.0.0-1012-awsUpgrade linux-image-realtime-64k-7.0Upgrade linux-image-oem-7.0Upgrade linux-image-nvidia-bos-64kUpgrade linux-image-realtimeUpgrade linux-image-realtime-hwe-26.04Upgrade linux-image-raspiUpgrade linux-image-aws-7.0Upgrade linux-image-7.0.0-2018-nvidia-bosUpgrade linux-image-nvidia-64k-hwe-26.04Upgrade linux-image-gcp-64k-7.0Upgrade linux-image-gcp-64kUpgrade linux-image-aws-64k-7.0Upgrade linux-image-7.0.0-1013-oemUpgrade linux-image-gke-hwe-26.04Upgrade linux-image-generic-hwe-24.04Upgrade linux-image-7.0.0-1018-nvidia-64kUpgrade linux-image-7.0.0-1014-azureUpgrade linux-image-raspi-realtime-7.0Upgrade linux-image-oem-26.04aUpgrade linux-image-realtime-64kUpgrade linux-image-7.0.0-1011-oracle-64kUpgrade linux-image-nvidia-64kUpgrade linux-image-nvidia-bosUpgrade linux-image-nvidia-7.0Upgrade linux-image-gke-64kUpgrade linux-image-7.0.0-1019-raspiUpgrade linux-image-oracle-64kUpgrade linux-image-7.0.0-1019-raspi-realtime | Sep 14, 2026 | Sep 7, 2026 |
Prioritise with Active Threat Intelligence
With curated Threat Intelligence, you can see which vulnerabilities truly put you at risk, prioritize what matters most, and act before attackers do.
Explore Intelligence Hub