SB2026040161 - Incomplete Blacklist to Cross-Site Scripting in Linux kernel kvm mmu
Published: April 1, 2026
Security Bulletin ID
SB2026040161
Severity
Low
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Local access
Highest impact
Denial of service
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 security vulnerability.
1) Incomplete Blacklist to Cross-Site Scripting (CVE-ID: CVE-2026-23402)
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to improper input validation in KVM's x86/mmu component when handling SPTE updates from host userspace. A local user can trigger a warning condition that leads to a system crash to cause a denial of service.
Exploitation requires access to host userspace and affects virtualized environments using KVM with EPT. The issue arises when modifying SPTEs outside KVM's write tracking scope.
Remediation
Install update from vendor's website.