CVE-2026-64555

HIGH
MEDIUM Priority: 0.01 BB Relevance: 43/100
Published: 2026-07-27 Modified: 2026-11-03 First seen: 2026-11-03 Status: active

Attack Surface

Low Complexity No Interaction Conf. Impact Integ. Impact Scope Change

CVSS Vector Breakdown

AV: Local
AC: Low
PR: Low
UI: None
S: Changed
C: High
I: High
A: High

Description

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.

Bug Bounty Relevance

43 / 100
✓ Low complexity
✓ No user interaction

CVSS Score

8.8 / 10.0 v3.1
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

EPSS — Exploitation Probability

0.13%
Raw Score 0.001290
Percentile 2.6%
Date 2026-11-14

EPSS Trend

2026-11-14
0.00129
2026-11-13
0.00129
2026-11-12
0.00129
2026-11-10
0.00129
2026-11-09
0.00129
2026-11-08
0.00129
2026-11-07
0.00129
2026-11-06
0.00129
2026-11-05
0.00129
2026-11-04
0.00129
2026-11-03
0.00129

Intelligence Sources

nvd ref →