{"cve":"CVE-2026-63940","nvd":{"published":"2026-07-19T16:17:12.540","modified":"2026-10-21T13:19:17.367","status":"Undergoing Analysis","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: SEV: Ignore Port I/O requests of length '0'\n\nExplicitly ignore Port I/O requests of length '0' (or count '0'), so that\nsetting up the software scratch area (and other code) doesn't have to\nworry about underflowing the length, and to allow for WARNing on trying\nto configure the scratch area with len==0.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H","score":9.3},"cwes":["CWE-190"],"references":["https://git.kernel.org/stable/c/2254972d4d69e279ba4e87bf0968eb08ad0d3c92","https://git.kernel.org/stable/c/3988bd2723de407ae90fa7a6f6029b4e60238c58","https://git.kernel.org/stable/c/3b6035bc6bff20e89752ce4358bc4c9a9d5883f2","https://git.kernel.org/stable/c/bbd3a27e4f99fdcad82d12d79c04a95dff1ff70b","https://git.kernel.org/stable/c/c30cde934c7813b4e3069765dac64ce3d31e34f2"],"products":[],"source":"nvd","synced_at":"2026-10-22T16:41:11.231219466+00:00"},"epss":{"cve":"CVE-2026-63940","score":0.00186,"percentile":0.0808,"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."]}