High 7.8Published Jul 19, 2026

CVE-2026-63970vsock/virtio: bind uarg before filling zerocopy skb

Updated under an hour ago (Oct 28, 2026, 7:40 AM ET)

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Exploited in the last 30 days

In the Linux kernel, the following vulnerability has been resolved: vsock/virtio: bind uarg before filling zerocopy skb virtio_transport_send_pkt_info() allocates or reuses the zerocopy uarg before entering the send loop, but virtio_transport_alloc_skb() still fills the skb before it inherits that uarg. When fixed-buffer vectored zerocopy hits MAX_SKB_FRAGS, io_sg_from_iter() may partially attach managed frags and return -EMSGSIZE. The rollback path call kfree_skb() to free an skb that carries SKBFL_MANAGED_FRAG_REFS but no uarg, so skb_release_data() falls through to ordinary frag unref. Pass the uarg into virtio_transport_alloc_skb() and bind it immediately before virtio_transport_fill_skb(). This keeps control or no-payload skbs untouched while ensuring success and rollback share one lifetime rule.

CVSS: 7.8 HIGH (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE): CWE-401
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Modified
Record last updated: Oct 19, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	581512a6dc939ef122e49336626ae159f3b8a345 builds before 72194f65050958e4c8e069adb6c5d89ef81ca197; from 581512a6dc939ef122e49336626ae159f3b8a345 before b62e2b2b4a50953ca952f3cd3f77dd62dc50fd5d; 581512a6dc939ef122e49336626ae159f3b8a345 builds before 5d317573f1d48e76cce5fb6250452b6e4102e0fb; 581512a6dc939ef122e49336626ae159f3b8a345 builds before 1e584c304cfb94a759417130b1fc6d30b30c4cce	CNA record
linux linux_kernel linux:linux_kernel	from 6.7 before 6.12.97; from 6.13 before 6.18.35; from 6.19 before 7.0.12; 7.1; 7.1; 7.1; 7.1; 7.1	NVD

References

References

https://git.kernel.org/stable/c/72194f65050958e4c8e069adb6c5d89ef81ca197	patch
https://git.kernel.org/stable/c/b62e2b2b4a50953ca952f3cd3f77dd62dc50fd5d	patch
https://git.kernel.org/stable/c/5d317573f1d48e76cce5fb6250452b6e4102e0fb	patch
https://git.kernel.org/stable/c/1e584c304cfb94a759417130b1fc6d30b30c4cce	patch

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.