{"cve":"CVE-2026-63970","nvd":{"published":"2026-07-19T16:17:16.063","modified":"2026-10-19T21:17:14.500","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nvsock/virtio: bind uarg before filling zerocopy skb\n\nvirtio_transport_send_pkt_info() allocates or reuses the zerocopy uarg\nbefore entering the send loop, but virtio_transport_alloc_skb() still\nfills the skb before it inherits that uarg. When fixed-buffer vectored\nzerocopy hits MAX_SKB_FRAGS, io_sg_from_iter() may partially attach\nmanaged frags and return -EMSGSIZE. The rollback path call kfree_skb()\nto free an skb that carries SKBFL_MANAGED_FRAG_REFS but no uarg, so\nskb_release_data() falls through to ordinary frag unref.\n\nPass the uarg into virtio_transport_alloc_skb() and bind it immediately\nbefore virtio_transport_fill_skb(). This keeps control or no-payload skbs\nuntouched while ensuring success and rollback share one lifetime rule.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8},"cwes":["CWE-416","CWE-401"],"references":["https://git.kernel.org/stable/c/1e584c304cfb94a759417130b1fc6d30b30c4cce","https://git.kernel.org/stable/c/5d317573f1d48e76cce5fb6250452b6e4102e0fb","https://git.kernel.org/stable/c/72194f65050958e4c8e069adb6c5d89ef81ca197","https://git.kernel.org/stable/c/b62e2b2b4a50953ca952f3cd3f77dd62dc50fd5d"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-21T03:43:09.190223697+00:00"},"epss":{"cve":"CVE-2026-63970","score":0.00176,"percentile":0.07032,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}