Google: sys-kernel/cchost-kernel-6_18, sys-kernel/csql-kernel-6_18, sys-kernel/lakitu-kernel-6_18, sys-kernel/lakitu-nc-kernel-6_18: security update to 20198.0.0

high Tenable Self-Hosted Container Security Plugin ID 475603

Description

There are packages installed that are affected by a vulnerability referenced in the following CVE:

- In the Linux kernel, the following vulnerability has been resolved: Drivers: hv: vmbus: Skip VMBus module
cleanup for non-nested root partition The VMBus module initialization function, hv_acpi_init(), currently
does nothing when running in the root partition and root is not nested in another VM. But the
initialization function reports success, so the VMBus module is indeed loaded. VMBus functionality is not
actually needed, but the VMBus module must be loaded so that hv_vmbus_exists() can answer correctly.
Furthermore, the mshv_root dependency on the VMBus module is needed as described in the commit message for
840b740a35bf ("mshv: Add conditional VMBus dependency"). Loading the VMBus module without actually
initializing it causes failures if the module should later be unloaded. The module unload code tries to
clean up things that were never initialized, resulting in memory faults and a panic. Fix this by having
VMBus module exit function perform the same check for non-nested root partition, and do nothing in such a
case, just like hv_acpi_init(). In the long run, the code that manages the Hyper-V provided SynIC should
be refactored to better coordinate the requirements of root partition scenarios and normal VM scenarios,
and to hopefully remove the hv_vmbus_exists() dependnecy between mshv_root and VMBus modules. Preventing
the current unload failure scenario is an expediency until such a refactoring is done. (CVE-2026-90097)

Solution

Update the sys-kernel/cchost-kernel-6_18 library and its related packages to version 20198.0.0 or later.

Plugin Details

Severity: High

ID: 475603

Version: Revision 1.1

Type: Local

Family: Google COS Security Checks

Published: 10/16/2026

Updated: 10/16/2026

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.7

Vendor

Vendor Severity: LOW

CVSS v2

Risk Factor: High

Base Score: 7.2

Temporal Score: 5.3

Vector: CVSS2#AV:L/AC:L/Au:N/C:C/I:C/A:C

CVSS Score Source: CVE-2026-90097

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 6.8

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

Exploit Ease: No known exploits are available

Vulnerability Publication Date: 9/17/2026

Reference Information

CVE: CVE-2026-90097

Detections

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