CVE-2026-98471 Linux CVE debrief

Who should care

Linux administrators and security teams responsible for KVM and SEV deployments should assess and apply cache maintenance for KVM SEV intra-host migrations to prevent potential data exposure. They should verify cache maintenance for KVM SEV intra-host migrations, assess potential data exposure due to stale CPU caches, and update to fixed kernel versions to prevent data exposure.

Why it matters

CVE-2026-98471 requires Linux administrators and security teams to assess and apply cache maintenance for KVM SEV intra-host migrations to prevent potential data exposure.

• Verify cache maintenance for KVM SEV intra-host migrations
• Assess potential data exposure due to stale CPU caches
• Update to fixed kernel versions to prevent data exposure

Technical summary

The Linux kernel vulnerability involves KVM and SEV intra-host migration, requiring manual cache maintenance on the source VM to prevent stale data in CPU caches. This vulnerability affects Linux administrators and security teams responsible for KVM and SEV deployments. The source VM is converted to a non-SEV VM, and KVM's memory reclaim flows won't trigger cache maintenance. Enforcing equivalent memory configurations is infeasible, as it would require a deep comparison of memslots. Relying on the destination VM to do cache maintenance isn't an option as KVM doesn't require identical guest memory configurations.

Defensive priority

Assess and apply cache maintenance for KVM SEV intra-host migrations

Recommended defensive actions

• Review and apply cache maintenance for KVM SEV intra-host migrations
• Verify system configurations and update to fixed kernel versions
• Monitor for potential data exposure due to stale CPU caches
• Assess potential data exposure due to stale CPU caches
• Verify cache maintenance for KVM SEV intra-host migrations
• Update to fixed kernel versions to prevent data exposure
• Track exceptions and retest remediated assets

Evidence notes

The CVE record and NVD entry provide details on the vulnerability, with references to kernel.org patches. Additional analysis indicates that Linux administrators and security teams should verify cache maintenance for KVM SEV intra-host migrations, assess potential data exposure due to stale CPU caches, and update to fixed kernel versions to prevent data exposure. Limited evidence suggests that KVM's memory reclaim flows won't trigger cache maintenance, e.g., when all guest memory is reclaimed in response to detaching from the mmu_not器

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.