{"cve":"CVE-2026-64308","nvd":{"published":"2026-07-25T10:17:11.917","modified":"2026-10-24T13:10:00.147","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ncrypto: ccp - Do not initialize SNP for ioctl(SNP_VLEK_LOAD)\n\nSashiko notes:\n\n> if SEV initialization fails and KVM is actively running normal VMs, could a\n> userspace process trigger this code path via /dev/sev ioctls (e.g.,\n> SEV_PDH_GEN) and zero out MSR_VM_HSAVE_PA globally? Would the next VMRUN\n> execution for an active VM trigger a general protection fault and crash the\n> host?\n\nThe SEV firmware docs for SNP_VLEK_LOAD note:\n\n> On SNP_SHUTDOWN, the VLEK is deleted.\n\nThat is, the initialization/shutdown wrapper here is pointless, because the\nfirmware immediately throws away the key anyway. Instead, refuse to do\nanything if SNP has not been previously initialized.\n\nThis is an ABI break: before, this was a no-op and almost certainly a\nmistake by userspace, and now it returns -ENODEV. ABI compatibility could be\nmaintained here by simply returning 0 in the check instead.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":[],"references":["https://git.kernel.org/stable/c/61cf5eef20657bff9ca235fe938a99ce5ff65c06","https://git.kernel.org/stable/c/8836801847b9479ac046cb18a24981e1b0b05e9d","https://git.kernel.org/stable/c/92567ed9306d5a3d1b007eb4faeff30cc3ffc3e4","https://git.kernel.org/stable/c/f91e9dbb5845d1e5abf1028e6df57dcf61583e1b"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-24T16:53:27.712498749+00:00"},"epss":{"cve":"CVE-2026-64308","score":0.00172,"percentile":0.06506,"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."]}