CVE-2026-72285 KVM: TDX: Reject concurrent change to CPUID entry count
A race condition in Linux KVM TDX allows attackers to trigger out-of-bounds memory access, potentially leading to code execution or privilege escalation.
- 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-2026-72285?
CVE-2026-72285 is a high-severity vulnerability in Linux, published on 15 Aug 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: TDX: Reject concurrent change to CPUID entry count
Reject KVM_TDX_INIT_VM if userspace changes cpuid.nent between the initial read and the subsequent copy of the initialization data.
tdx_td_init() first reads user_data->cpuid.nent to size the flexible kvm_tdx_init_vm copy. The copied structure also contains cpuid.nent, and that field can differ from the value used to size the allocation if userspace modifies the input concurrently. setup_tdparams_cpuids() later passes init_vm->cpuid.nent to kvm_find_cpuid_entry2(), which uses it as the array bound for the copied entries.
Require the copied count to match the value used to size the allocation so that CPUID parsing cannot access beyond the entries actually copied.
Which versions are affected by CVE-2026-72285?
How do I fix CVE-2026-72285?
Apply the vendor's patch.
Is CVE-2026-72285 being exploited?
There is no known exploitation of CVE-2026-72285 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-72285, GHSA-725c-hm4j-27fv, UBUNTU-CVE-2026-72285.