CVE-2026-64287 KVM: arm64: Bound used_lrs when flushing the pKVM hyp vCPU
A missing bounds check in KVM arm64 allows a host to trigger out-of-bounds memory access at EL2, potentially leading to code execution or privilege escalation.
- 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-2026-64287?
CVE-2026-64287 is a high-severity memory corruption vulnerability in Linux kernel, published on 25 Jul 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: Bound used_lrs when flushing the pKVM hyp vCPU
flush_hyp_vcpu() copies the host vGIC state into the hyp's private vCPU on every run. The vGIC list register save and restore use used_lrs as their loop bound and expect it to stay within the number of implemented list registers. While this is generally the case, flush_hyp_vcpu() copies vgic_v3 verbatim and does not enforce this, so a value provided by the host is used at EL2 to index vgic_lr[] and access ICH_LR<n>_EL2 (host -> EL2).
Fix by clamping used_lrs to the number of implemented list registers after the copy, as the trusted path already does in vgic_flush_lr_state(). The number of implemented list registers is constant after init, so it is replicated once from kvm_vgic_global_state.nr_lr into hyp_gicv3_nr_lr rather than read on every entry.
Weakness: CWE-125
Which versions are affected by CVE-2026-64287?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-64287?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-64287 being exploited?
There is no known exploitation of CVE-2026-64287 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-93875, BELL-CVE-2026-64287, DEBIAN-CVE-2026-64287, GHSA-hfcp-qwvj-9247, ROOT-OS-DEBIAN-13-CVE-2026-64287, ROOT-OS-UBUNTU-2204-CVE-2026-64287 and 1 more.