{"id":"CVE-2026-98718","title":"KVM: SEV: Do cache maintenance on the source VM *before* clearing SEV state","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: SEV: Do cache maintenance on the source VM *before* clearing SEV state\n\nExplicitly flush caches after intra-host migration before clearing \"SEV\nactive\" on the sour…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 37dfb676fafd1eef36fe0bb649607afbb0d5521b < 8b7d4f68fef96cebe0b6dbb6e5607772337f7369","Linux >= d4cc2dff12116a700add601c0262132cc26e1b2c < de83ff6a4d8f3618473bedb3c4400020c22e8a8a","Linux >= 93de2a6a4b91b72607136dd656edf03fb399d27f < 973ea70393e885e540f714904e51bc6cac80e3d7","Linux >= 6.18.55 < 6.18.56","Linux >= 7.2.9 < 7.2.10","Linux 7.3-rc5"],"published":"2026-10-18","updated":"2026-10-18","sourceUpdated":"2026-10-18T15:46:53.611Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98718","references":[{"url":"https://git.kernel.org/stable/c/8b7d4f68fef96cebe0b6dbb6e5607772337f7369"},{"url":"https://git.kernel.org/stable/c/de83ff6a4d8f3618473bedb3c4400020c22e8a8a"},{"url":"https://git.kernel.org/stable/c/973ea70393e885e540f714904e51bc6cac80e3d7"}],"tags":["cve.org"],"ingestedAt":"2026-10-18T16:47:32.509Z","slug":"CVE-2026-98718","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nKVM: SEV: Do cache maintenance on the source VM *before* clearing SEV state\n\nExplicitly flush caches after intra-host migration before clearing \"SEV\nactive\" on the source VM, as doing cache maintenance afterwards creates a\ntiny window where memory reclaim could return memory to the host without\nperforming a cache flush, e.g. as pointed out by Sashiko:\n\n  CPU1 in sev_migrate_from():\n    src->active = false;\n\n  CPU2 running concurrent unmap:\n    Since active is false, the automatic cache flush in\n    sev_guest_memory_reclaimed is skipped.\n    The host frees and reallocates the page.\n\n  CPU1 in sev_migrate_from():\n    sev_writeback_caches(src_kvm);\n    Executes a hardware cache flush (wbnoinvd), which writes the guest's old\n    dirty ciphertext over the new page owner's data.\n\n## Affected\n\n- `Linux >= 37dfb676fafd1eef36fe0bb649607afbb0d5521b < 8b7d4f68fef96cebe0b6dbb6e5607772337f7369`\n- `Linux >= d4cc2dff12116a700add601c0262132cc26e1b2c < de83ff6a4d8f3618473bedb3c4400020c22e8a8a`\n- `Linux >= 93de2a6a4b91b72607136dd656edf03fb399d27f < 973ea70393e885e540f714904e51bc6cac80e3d7`\n- `Linux >= 6.18.55 < 6.18.56`\n- `Linux >= 7.2.9 < 7.2.10`\n- `Linux 7.3-rc5`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}