{"id":"CVE-2026-64285","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-64285","generatedAt":"2026-10-28T03:26:30.000Z","title":"In the Linux kernel, the following vulnerability has been resolved: KVM: SEV: Pin source page for write when adding CPUID data for SNP guest When populating a guest_memfd instance with the initial CPUID data for an SNP guest, acquire a writable pin on…","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: SEV: Pin source page for write when adding CPUID data for SNP guest\n\nWhen populating a guest_memfd instance with the initial CPUID data for an\nSNP guest, acquire a writable pin on the source page as KVM will write back\nthe \"correct\" CPUID information if the userspace provided data is rejected\nby trusted firmware.  Because KVM writes to the source page using a kernel\nmapping, pinning for read could result in KVM clobbering read-only memory.\n\nNote, well-behaved VMMs are unlikely to be affected, as CPUID information\nis almost always dynamically generated by userspace, i.e. it's unlikely for\nthe CPUID information to be backed by a read-only mapping.\n\n[sean: rewrite shortlog and changelog, tag for stable@]","published":"2026-07-25T10:17:09.000Z","lastModified":"2026-08-17T05:17:28.000Z","status":"Analyzed","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","cvss":{"version":"3.1","score":5.5,"severity":"MEDIUM","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"},"cwe":[],"affected":["linux/linux kernel"],"epss":{"score":0.00143,"percentile":0.03601,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.14%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://git.kernel.org/stable/c/dcdb476f5fc5701ec06c23efe3e3529f07ca391e","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/f13e900599089b10113ceb36013423f0837c6792","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-64285","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}