{"cve":"CVE-2026-23057","nvd":{"published":"2026-02-04T17:16:16.380","modified":"2026-06-17T10:20:47.133","status":"Deferred","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nvsock/virtio: Coalesce only linear skb\n\nvsock/virtio common tries to coalesce buffers in rx queue: if a linear skb\n(with a spare tail room) is followed by a small skb (length limited by\nGOOD_COPY_LEN = 128), an attempt is made to join them.\n\nSince the introduction of MSG_ZEROCOPY support, assumption that a small skb\nwill always be linear is incorrect. In the zerocopy case, data is lost and\nthe linear skb is appended with uninitialized kernel memory.\n\nOf all 3 supported virtio-based transports, only loopback-transport is\naffected. G2H virtio-transport rx queue operates on explicitly linear skbs;\nsee virtio_vsock_alloc_linear_skb() in virtio_vsock_rx_fill(). H2G\nvhost-transport may allocate non-linear skbs, but only for sizes that are\nnot considered for coalescence; see PAGE_ALLOC_COSTLY_ORDER in\nvirtio_vsock_alloc_skb().\n\nEnsure only linear skbs are coalesced. Note that skb_tailroom(last_skb) > 0\nguarantees last_skb is linear.","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/0386bd321d0f95d041a7b3d7b07643411b044a96","https://git.kernel.org/stable/c/568e9cd8ed7ca9bf748c7687ba6501f29d30e59f","https://git.kernel.org/stable/c/63ef9b300bd09e24c57050c5dbe68feedce42e72"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:22:27.261130201+00:00"},"epss":{"cve":"CVE-2026-23057","score":0.00199,"percentile":0.09727,"date":"2026-11-01"},"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."]}