CVE-2026-72277 KVM: arm64: nv: Inject SEA if guest VNCR isn't normal memory
A flaw in Linux KVM arm64 nested virtualization allows a guest to cause a system error and denial of service by mapping VNCR to non-memory regions.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-72277?
CVE-2026-72277 is a critical denial of service 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: arm64: nv: Inject SEA if guest VNCR isn't normal memory
When constructing an L1 VNCR mapping, KVM unconditionally uses cacheable memory attributes, even if the underlying PFN isn't memory. This gets particularly hairy if the endpoint doesn't support cacheable memory attributes, potentially throwing an SError on writeback...
While KVM does permit cacheable memory attributes on certain PFNMAP VMAs, kvm_translate_vncr() isn't currently grabbing the VMA. So do the simpler thing for now and just reject everything that isn't memory.
Which versions are affected by CVE-2026-72277?
How do I fix CVE-2026-72277?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-72277 being exploited?
There is no known exploitation of CVE-2026-72277 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-72277, DEBIAN-CVE-2026-72277, GHSA-x8qc-pvh3-2vf6, UBUNTU-CVE-2026-72277.