CVE-2026-89932 KVM: nVMX: Always flush vpid02 on first use
A flaw in Linux KVM allows reading stale TLB entries from previous VM lifetimes, potentially disclosing sensitive memory data.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-89932?
CVE-2026-89932 is a high-severity vulnerability in Linux, published on 16 Sep 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: nVMX: Always flush vpid02 on first use
Make sure vpid02 is always flushed on first use by setting last_vpid=0 when allocating vpid02. nested_vmx_transition_tlb_flush() will always detect a VPID change on first VM-Enter after VMXON, because VPID=0 in vmcs12 is not allowed if L1 enables VPID.
This avoids using stale TLB entries from a previous lifetime of the VPID, that might have been associated with a different vCPU (or a completely different VM).
Note that last_vpid is already being initialized as 0 when the vCPU is created, but it is not reset when vpid02 is freed on VMXOFF. Hence, the problem can only occur if L1 does VMXOFF -> VMXON, runs an L2, and KVM happens to reuse a VPID that has TLB entries on the physical CPU.
Which versions are affected by CVE-2026-89932?
How do I fix CVE-2026-89932?
Apply the vendor's patch.
Is CVE-2026-89932 being exploited?
There is no known exploitation of CVE-2026-89932 in the wild and no public exploit code.
Sources
Also known as AZL-101610, BELL-CVE-2026-89932, DEBIAN-CVE-2026-89932, GHSA-8q77-gpg3-wgrc, UBUNTU-CVE-2026-89932.