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 19999.44.106

critical Tenable Cloud Security Plugin ID 475537

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: KVM: arm64: Remove VM-wide VNCR
mapping counter The global VNCR mapping counter is used to decide whether an L1 provided VNCR page is
mapped in L0 on any CPU at the point of dealing with a TLB invalidation. It is incremented when a mapping
is made in the fixmap, and decremented when unmapped. As it turns out, this tracking has several flaws: -
we are trying to invalidate TLBs, and the mapping is only an opportunistic consequence of the TLB.
Checking this counter to decide whether a TLB needs to be invalidated may result in missed invalidations.
- an L1 vcpu invalidating its own TLB (a very likely case) will not succeed in invalidating the VNCR
pseudo TLB because that page is not mapped in L0 at this stage. Given that this tracking fails at
delivering the minimum guarantees that are required and is only a performance optimisation, remove it
completely. (CVE-2026-89915)

Solution

Update the sys-kernel/cchost-kernel-6_18 library and its related packages to version 19999.44.106 or later.

Plugin Details

Severity: Critical

ID: 475537

Version: Revision 1.1

Type: Local

Family: Google COS Security Checks

Published: 10/16/2026

Updated: 10/16/2026

Risk Information

VPR

Risk Factor: Medium

Score: 5

Percentile: 92.99

Vendor

Vendor Severity: HIGH

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-2026-89915

CVSS v3

Risk Factor: Critical

Base Score: 9.3

Temporal Score: 8.1

Vector: CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:C/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: 9/16/2026

Reference Information

CVE: CVE-2026-89915

Detections

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