SB2026050750 - Improper input validation in Linux kernel x86 kvm

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Main Vulnerability Database SB2026050750

SB2026050750 - Improper input validation in Linux kernel x86 kvm

Published: May 7, 2026

Security Bulletin ID SB2026050750
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Denial of service

Breakdown by Severity

Medium 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Improper input validation (CVE-ID: CVE-2026-43265)

CWE-ID: CWE-20 - Improper input validation

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote user to cause a denial of service.

The vulnerability exists due to improper state validation in KVM x86 nested virtualization handling when processing userspace-supplied MP_STATE or injected events for a blocked vCPU while L2 is active. A remote user can place the vCPU into an invalid state to cause a denial of service.

The issue can result in a spurious userspace exit, typically with KVM_EXIT_UNKNOWN, after exiting a blocking state.


Remediation

Install update from vendor's website.

References