Linux kernel KVM SEV skips freeing CPU mask on VM destruction
Key facts
- Attack vector
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- Privileges required
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- User interaction
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- Attack complexity
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- Impact type
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- Confidentiality · integrity · availability
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- Fix status
- Partial Red Hat: 3 without a fix
No CVSS vector from any source. Fix status from CNA and Red Hat.
Summary
The Linux kernel from 6.17 is affected. The KVM SEV code skips freeing its have_run_cpus CPU mask during VM destruction when intra-host migration has turned an SEV VM into a non-SEV VM. The sources do not describe an attack, and the flaw is not listed in CISA KEV and no public exploit is linked.
Written with Claude Haiku 5.5 from the sources below · 2026-11-07
Description from the CNA
In the Linux kernel, the following vulnerability has been resolved: KVM: SEV: Free have_run_cpus during VM destruction even if VM is no longer SEV Unconditionally free SEV's "have run CPUs" cpumask in the VM destroy path, i.e. even for what appear to be non-SEV VMs, as an SEV VM becomes a non-SEV VM if its state is intra-host migrated. Alternatively, the mask could be freed in sev_migrate_from() when "converting" the source VM, but that gets annoying because ideally KVM would nullify the mask to guard against UAF, and nullifying the mask would need be conditioned on CPUMASK_OFFSTACK=y. Freeing the mask during sev_migrate_from() is also not robust against other KVM bugs, though that's kind of a moot point since any such bugs would show up even if sev->active is never set. I.e. KVM must get that side of things correct. But, that's not a great reason to add more code just to make things marginally less robust.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
Upgrade the Linux kernel to 6.18.55, 7.2.9 or 7.3. Red Hat Enterprise Linux 10 and Red Hat OpenShift Container Platform 4 and 5 are affected, and Red Hat lists no available plan for them.
Written with Claude Haiku 5.5 from the sources below · 2026-11-07
- Fix · CNA Linux (Linux) Fixed in 6.18.55, 7.2.9, 7.3
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 5 | Affected | No fix yet: Fix deferred |
Not affected: 4 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-18 Threatist record created from CVE-2026-98472
- 2026-10-18 Alias added: GHSA-qccv-gmm4-2g2g
- 2026-10-19 Fix available: Linux/[email protected] · CNA
- 2026-10-20 Affected versions changed · Red Hat
- 2026-10-20 CVSS score added · Red Hat
- 2026-11-07 Affected versions changed · Red Hat
References
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Sources
- CVE-2026-98472 · CVE Program
- CVE-2026-98472 · NVD
- FIRST EPSS
- GHSA-qccv-gmm4-2g2g · GitHub Advisory Database · CC BY 4.0
- CVE-2026-98472 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences