Detections
Analytics

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

medium Tenable Cloud Security Plugin ID 475727

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: Handle VNCR TLB
 invalidation race with vcpu_put() VNCR unmapping While VNCR TLB invalidation always occurs under the MMU
 lock, vcpu_put() doesn't, while it unmaps the VNCR page. The problem is that the invalidation evaluates
 vncr_tlb::cpu to decide whether an unmapping needs to take place (cpu != -1) before performing it. On the
 other hand, this_cpu_reset_vncr_fixmap() unconditionally unmaps if L1_VNCR_MAPPED is set. These two
 obviously can race, with a TOCTOU pattern on the TLBI path, and a BUG_ON() on the vcpu_put() path. And the
 two can end-up calling vncr_fixmap(-1), with extra lethal effects. Move the reset of vncr_tlb::cpu to -1
 to a common function, and make this update atomic so that only a single thread can reset the field and
 perform the corresponding unmap. The vcpu_put() still need to unconditionally unmap the current VNCR to
 close another ugly race. Finally, the assignment of vncr_tlb::cpu is moved to be kept in sync with the
 actual mapping, similar to L1_VNCR_MAPPED being set. (CVE-2026-89917)

Solution

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

See Also

https://storage.googleapis.com/cos-oval-vulnerability-feed/cos-138.oval.xml.tar.gz

Plugin Details

Severity: Medium

ID: 475727

Version: Revision 1.1

Type: Local

Published: 10/16/2026

Updated: 10/16/2026

Risk Information

VPR

Risk Factor: Medium

Score: 4.3

Percentile: 53.52

Vendor

Vendor Severity: LOW

CVSS v2

Risk Factor: Medium

Base Score: 4.7

Temporal Score: 3.5

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

CVSS Score Source: CVE-2026-89917

CVSS v3

Risk Factor: Medium

Base Score: 6.3

Temporal Score: 5.5

Vector: CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:N/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-2026-89917