CVE-2026-98718
Received
Received - Intake
Cache Maintenance Flaw in Linux KVM SEV
Vulnerability report for CVE-2026-98718, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-10-18
Last updated on: 2026-10-18
Assigner: kernel.org
Description
Description
In the Linux kernel, the following vulnerability has been resolved:
KVM: SEV: Do cache maintenance on the source VM *before* clearing SEV state
Explicitly flush caches after intra-host migration before clearing "SEV
active" on the source VM, as doing cache maintenance afterwards creates a
tiny window where memory reclaim could return memory to the host without
performing a cache flush, e.g. as pointed out by Sashiko:
CPU1 in sev_migrate_from():
src->active = false;
CPU2 running concurrent unmap:
Since active is false, the automatic cache flush in
sev_guest_memory_reclaimed is skipped.
The host frees and reallocates the page.
CPU1 in sev_migrate_from():
sev_writeback_caches(src_kvm);
Executes a hardware cache flush (wbnoinvd), which writes the guest's old
dirty ciphertext over the new page owner's data.
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| Linux | Linux | 37dfb676fafd1eef36fe0bb649607afbb0d5521b |
| Linux | Linux | d4cc2dff12116a700add601c0262132cc26e1b2c |
| Linux | Linux | 93de2a6a4b91b72607136dd656edf03fb399d27f |
| Linux | Linux | 6.18.55 |
| Linux | Linux | 7.2.9 |
| Linux | Linux | 7.3-rc5 |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
