CVE intelligence

CVE-2026-64555

Vulnerability intelligence

Published Jul 27, 2026Sources checked Oct 8, 2026

8.8HIGHCVSS out of 10

What this means

Review the available evidence

CVE-2026-64555 and is rated High severity with a CVSS score of 8.8. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.

CISA KEVNot listedBased on the latest collected catalog

EPSS0.1%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-64555?

In the Linux kernel, the following vulnerability has been resolved:

KVM: arm64: nv: Fix SPSR_EL2 restore in kvm_hyp_handle_mops()

kvm_hyp_handle_mops() resets the single-step state machine as part of rewinding state for a MOPS exception by modifying vcpu_cpsr() and writing the result directly into hardware.

In the case of nested virtualization, vcpu_cpsr() is a synthetic value such that the rest of KVM can deal with vEL2 cleanly. That means the value requires translation before being written into hardware, which is unfortunately missing from the MOPS handler.

Fix it by directly modifying SPSR_EL2 and avoiding the synthetic state altogether, which will be resynchronized on the next 'full' exit back to KVM.

Source: NVD