SB20260824254 - Improper access control in Linux kernel vhost driver



SB20260824254 - Improper access control in Linux kernel vhost driver

Published: August 24, 2026

Security Bulletin ID SB20260824254
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Local access
Highest impact Code execution

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Improper access control (CVE-ID: CVE-2026-74580)

CWE-ID: CWE-284 - Improper Access Control

CVSSv4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]


The vulnerability allows a local user to access memory outside the intended IOTLB-mapped region.

The vulnerability exists due to improper access control in the vhost vring metadata cache in drivers/vhost/vhost.c when reconfiguring vring addresses or vring size through vhost ioctls while a device IOTLB is attached. A local user can issue crafted vring reconfiguration ioctls after populating the metadata cache to access memory outside the intended IOTLB-mapped region.

The issue occurs because stale cached metadata mappings may continue to be used after live vring reconfiguration, causing subsequent used ring updates or descriptor fetches to use translations based on the old mapping.


Remediation

Install update from vendor's website.