CVE-2026-31592
Description
A flaw was found in the Linux kernel's KVM (Kernel-based Virtual Machine) subsystem. A local user could exploit a concurrency issue by failing to properly protect the sev_mem_enc_register_region() function with the kvm->lock. This can lead to an unstable state if KVM initialization fails, resulting in a general protection fault and a null-pointer dereference. The most important consequence is a denial of service, causing the system to crash.
Statement
sev_mem_enc_register_region() is now fully serialized with kvm->lock, closing races in SEV memory region registration. Red Hat recommends patched KVM kernels for SEV deployments.
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 | 5.5 | N/A |
| Attack Vector | Local | Local | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | Low | Low | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | None | None | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | High | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Integrity,Availability
Technical Impact: Modify Application Data; DoS: Instability; DoS: Crash, Exit, or Restart
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