CVE-2026-63970
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.
Affected versions
Linux kernel versions
6.7
and later are affected. Fixed in
6.18.35,
7.0.12,
7.1
and their respective stable series.
References
3 totalFrequently asked questions
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What is CVE-2026-63970?
CVE-2026-63970 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 6.7 onward and has been patched in 6.18.35, 7.0.12 and 7.1. CVE-2026-63970 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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Is there a patch available for CVE-2026-63970?
Yes — CVE-2026-63970 has been patched. Fixed versions include 6.18.35, 7.0.12 and 7.1. If you are running Linux kernel 6.7 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-63970 actively exploited?
No — CVE-2026-63970 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.