CVE-2026-63970 Affecting linux-6.12 package, versions <6.12.100-1~deb12u1


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.18% (8th percentile)

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  • Snyk IDSNYK-ECHOLATEST-LINUX612-18579128
  • published7 Aug 2026
  • disclosed19 Jul 2026

Introduced: 19 Jul 2026

CVE-2026-63970  (opens in a new tab)

How to fix?

Upgrade Echo:latest linux-6.12 to version 6.12.100-1~deb12u1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream linux-6.12 package and not the linux-6.12 package as distributed by Echo. See How to fix? for Echo:latest relevant fixed versions and status.

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 Base Scores

version 3.1