CVE-2026-98472 KVM: SEV: Free have_run_cpus during VM destruction even if VM is no longer SEV
A use-after-free vulnerability in Linux KVM SEV allows local attackers with high privileges to cause denial of service or escalate privileges.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-98472?
CVE-2026-98472 is an use after free vulnerability in Linux, published on 18 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
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.
Which versions are affected by CVE-2026-98472?
How do I fix CVE-2026-98472?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-98472 being exploited?
There is no known exploitation of CVE-2026-98472 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-98472, DEBIAN-CVE-2026-98472, GHSA-qccv-gmm4-2g2g, UBUNTU-CVE-2026-98472.