{"cve":"CVE-2026-98568","nvd":{"published":"2026-10-18T16:17:09.000","modified":"2026-10-19T10:19:14.750","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nvxlan: use one headroom snapshot for neighbour replies\n\nvxlan_na_create() samples LL_RESERVED_SPACE() to size the reply skb and then\nsamples it again to reserve headroom. A concurrent vxlan_changelink() can\nupdate needed_headroom between the two reads, creating a TOCTOU race. The\nsecond value can exceed the allocation and make the Ethernet header write out\nof bounds.\n\nThe race is reproducible on the unpatched kernel. It occurred when\nvxlan_na_create() generated a neighbour reply while vxlan_changelink() changed\nthe link headroom. KASAN caught a four-byte write two bytes beyond a 704-byte\nskbuff_small_head allocation.\n\nSnapshot the headroom once and use that value for both allocation and\nreservation.","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/315d42ca39f69846662961c25dcf2bb07c350d14","https://git.kernel.org/stable/c/45a67662bf8ce3aa5643accf98d328dfbb47eaf6","https://git.kernel.org/stable/c/481506a756dcd828ef42391cb08f38d8d96d38fc","https://git.kernel.org/stable/c/a3c5eb6e382dd426a5e7eb08608897ed57167ff7","https://git.kernel.org/stable/c/ff022fd9d0f0282c575e11778b96bd1b637503eb"],"products":[],"source":"nvd","synced_at":"2026-10-19T23:00:53.604569364+00:00"},"epss":{"cve":"CVE-2026-98568","score":0.002,"percentile":0.09761,"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."]}