Google: sys-kernel/cchost-kernel-6_12, sys-kernel/csql-kernel-6_12, sys-kernel/lakitu-kernel-6_12, sys-kernel/lakitu-nc-kernel-6_12: security update to 19506.224.7

medium Tenable Self-Hosted Container Security Plugin ID 469526

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: SVM: Set/clear CR8 write
interception when AVIC is (de)activated Explicitly set/clear CR8 write interception when AVIC is
(de)activated to fix a bug where KVM leaves the interception enabled after AVIC is activated. E.g. if KVM
emulates INIT=>WFS while AVIC is deactivated, CR8 will remain intercepted in perpetuity. On its own, the
dangling CR8 intercept is "just" a performance issue, but combined with the TPR sync bug fixed by commit
d02e48830e3f ("KVM: SVM: Sync TPR from LAPIC into VMCB::V_TPR even if AVIC is active"), the danging
intercept is fatal to Windows guests as the TPR seen by hardware gets wildly out of sync with reality.
Note, VMX isn't affected by the bug as TPR_THRESHOLD is explicitly ignored when Virtual Interrupt Delivery
is enabled, i.e. when APICv is active in KVM's world. I.e. there's no need to trigger
update_cr8_intercept(), this is firmly an SVM implementation flaw/detail. WARN if KVM gets a CR8 write
#VMEXIT while AVIC is active, as KVM should never enter the guest with AVIC enabled and CR8 writes
intercepted. [Squash fix to avic_deactivate_vmcb. - Paolo] (CVE-2026-43483)

Solution

Update the sys-kernel/cchost-kernel-6_12 library and its related packages to version 19506.224.7 or later.

Plugin Details

Severity: Medium

ID: 469526

Version: Revision 1.6

Type: Local

Family: Google COS Security Checks

Published: 10/3/2026

Updated: 10/6/2026

Supported Sensors: Tenable Cloud Security, Tenable Self-Hosted Container Security

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.71

Vendor

Vendor Severity: MEDIUM

CVSS v2

Risk Factor: Medium

Base Score: 4.6

Temporal Score: 3.4

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

CVSS Score Source: CVE-2026-43483

CVSS v3

Risk Factor: Medium

Base Score: 5.5

Temporal Score: 4.8

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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: 4/30/2026

Reference Information

CVE: CVE-2026-43483

Detections

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