CVE-2026-64555
Description
A flaw was found in the Linux kernel's Kernel-based Virtual Machine (KVM) for ARM64 architecture, specifically affecting nested virtualization. The kvm_hyp_handle_mops() function, responsible for handling certain virtualization operations, incorrectly restored the SPSR_EL2 register. This occurred because a synthetic value used for nested virtualization was written directly to hardware without proper translation, leading to an improper reset of the single-step state machine. This could potentially impact the stability or security of nested virtualized environments.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.5 | N/A | 8.8 |
| Attack Vector | Local | N/A | Local |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Changed |
| Confidentiality | None | N/A | High |
| Integrity Impact | None | N/A | High |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Understanding the Weakness (CWE)
Other,Integrity
Technical Impact: Unexpected State; Quality Degradation
The program could wind up using the wrong number and generate incorrect results. If the number is used to allocate resources or make a security decision, then this could introduce a vulnerability.
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