SB2026102378 - Incorrect comparison in Linux kernel x86 kvm

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Main Vulnerability Database SB2026102378

SB2026102378 - Incorrect comparison in Linux kernel x86 kvm

Published: October 23, 2026

Security Bulletin ID SB2026102378
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Local access
Highest impact Data manipulation

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Incorrect comparison (CVE-ID: CVE-2026-99082)

CWE-ID: CWE-697 - Incorrect Comparison

CVSSv4: 2 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]


The vulnerability allows a local user to bypass KVM's write tracking for guest RAM and cause continued use of stale guest memory translations.

The vulnerability exists due to incorrect memslot generation comparisons in the x86 KVM per-vCPU MMIO cache when caching and validating entries across normal and system management mode address spaces. A local user can cause a stale cache entry to misclassify a valid guest RAM access as KVM_EXIT_MMIO after an SMM memslot update, allowing completion through the virtual machine monitor's RAM address space to bypass write tracking and leave shadow translations stale if the modified page backs a nested EPT table.


Remediation

Install update from vendor's website.

References