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 19804.0.0

medium Tenable Cloud Security Plugin ID 471273

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: perf/x86/intel: Improve validation and
configuration of ACR masks Currently there are several issues on the user space ACR mask validation and
configuration. - The validation for user space ACR mask (attr.config2) is incomplete, e.g., the ACR mask
could include the index which belongs to another ACR events group, but it's not validated. - An early
return on an invalid ACR mask caused all subsequent ACR groups to be skipped. - The stale hardware ACR
mask (hw.config1) is not cleared before setting new hardware ACR mask. The following changes address all
of the above issues. - Figure out the event index group of an ACR group. Any bits in the user-space mask
not present in the index group are now dropped. - Instead of an early return on invalid bits, drop only
the invalid portions and continue iterating through all ACR events to ensure full configuration. -
Explicitly clear the stale hardware ACR mask for each event prior to writing the new configuration.
Besides, a non-leader event member of ACR group could be disabled in theory. This could cause bit-shifting
errors in the acr_mask of remaining group members. But since ACR sampling requires all events to be
active, this should not be a big concern in real use case. Add a "FIXME" comment to notice this risk.
(CVE-2026-53370)

Solution

Update the sys-kernel/cchost-kernel-6_18 library and its related packages to version 19804.0.0 or later.

Plugin Details

Severity: Medium

ID: 471273

Version: Revision 1.5

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: 23.72

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-2026-53370

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: 5/26/2026

Reference Information

CVE: CVE-2026-53370

Detections

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