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 19862.0.0

high Tenable Self-Hosted Container Security Plugin ID 470843

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: arm64: tlb: Flush walk cache when
unsharing PMD tables When huge_pmd_unshare() is called to unshare a PMD table, the
tlb_unshare_pmd_ptdesc() function sets tlb->unshared_tables=true but the aarch64 tlb_flush() only checked
tlb->freed_tables to determine whether to use TLBF_NONE (vae1is, invalidates walk cache) or
TLBF_NOWALKCACHE (vale1is, leaf-only). This caused the stale PMD page table entry to remain in the walk
cache after unshare, potentially leading to incorrect page table walks. Fix by including unshared_tables
in the check, so that when unsharing tables, TLBF_NONE is used and the walk cache is properly invalidated.
Here is the detailed distinction between vae1is and vale1is: | Instruction Combination | Actual
Invalidation Scope | | ------------------------ | --------------------------------------------------| |
`VAE1IS` + TTL=`0` | All entries at all levels (full invalidation) | | `VAE1IS` + TTL=`2` (L2) | Non-leaf
at Level 0/1 + leaf at Level 2 | | `VALE1IS` + TTL=`0` | Leaf entries at all levels (non-leaf not cleared)
| | `VALE1IS` + TTL=`2` (L2) | Leaf entry at Level 2 only | (CVE-2026-63875)

Solution

Update the sys-kernel/cchost-kernel-6_18 library and its related packages to version 19862.0.0 or later.

Plugin Details

Severity: High

ID: 470843

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: Medium

Score: 4.9

Percentile: 58.13

Vendor

Vendor Severity: LOW

CVSS v2

Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5

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

CVSS Score Source: CVE-2026-63875

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: 6/22/2026

Reference Information

CVE: CVE-2026-63875

Detections

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