Detections
Analytics

Google: sys-kernel/cchost-kernel-6_12, sys-kernel/csql-kernel-6_12, sys-kernel/csql-kernel-6_6, sys-kernel/lakitu-kernel-6_12, sys-kernel/lakitu-kernel-6_6, sys-kernel/lakitu-nc-kernel-6_12, sys-kernel/lakitu-nc-kernel-6_6, sys-kernel/lakitu-vgpu-kernel-6_6: security update to 19216.532.135

medium Tenable Self-Hosted Container Security Plugin ID 469221

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: Bump asid_generation on CPU
 online to avoid ASID collision after hotplug If a vCPU stays scheduled out (or blocked) while the last
 pCPU it ran on goes through a hotplug cycle (online->offline->online), and the vCPU then resumes execution
 on the same pCPU, then it is possible for it to run with an ASID that has now been assigned to a different
 vCPU, resulting in stale TLB translations being used. svm_enable_virtualization_cpu() resets
 asid_generation to 1 and sets next_asid to max_asid + 1 on every CPU online event, including hotplug
 cycles. Because next_asid starts beyond the pool boundary, the first call to new_asid() after an online
 event always wraps the pool, incrementing asid_generation to 2 and assigning ASIDs starting from min_asid.
 Consider two vCPUs from different VMs, vCPU-A pinned to CPU-X holding asid_generation=2 and ASID=N from
 before the hotplug event: 1. CPU-X goes offline and back online: asid_generation resets to 1, next_asid =
 max_asid + 1. 2. One or more vCPUs migrate to CPU-X and call new_asid(), wrapping the pool and consuming
 ASIDs starting from min_asid. Eventually vCPU-B from a different VM is assigned asid_generation=2, ASID=N
 — the same ASID that vCPU-A held before the hotplug. 3. vCPU-A enters pre_svm_run() on CPU-X:
 current_vmcb->cpu is unchanged so the migration branch is skipped. Its saved asid_generation=2 matches
 sd->asid_generation=2, so the generation check silently passes and vCPU-A continues running with ASID=N —
 the same ASID just freshly assigned to vCPU-B. Both vCPUs from different VMs now run on CPU-X with the
 same ASID, causing them to share NPT TLB entries and producing stale translations. The collision manifests
 as a KVM internal error (Suberror: 1, emulation failure). The NPT page fault reports a faulting GPA far
 outside the VM's physical memory range — a sign of stale TLB translations being used. KVM falls back to
 instruction emulation, which fails on FPU/XSave instructions (XRSTOR, STMXCSR) that the emulator does not
 implement. Fix this by incrementing asid_generation instead of resetting it to 1 in
 svm_enable_virtualization_cpu(). On module load, asid_generation starts at 0 (memset) and the increment
 produces 1, identical to the old behaviour. On subsequent hotplug cycles the generation advances beyond
 any value a vCPU previously observed on this CPU, so the generation check in pre_svm_run() reliably forces
 new_asid() on every vCPU after every hotplug cycle. (CVE-2026-68093)

Solution

Update the sys-kernel/cchost-kernel-6_12 library and its related packages to version 19216.532.135 or later.

See Also

https://storage.googleapis.com/cos-oval-vulnerability-feed/cos-125.oval.xml.tar.gz

Plugin Details

Severity: Medium

ID: 469221

Version: Revision 1.5

Type: Local

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: 4.4

Percentile: 57.58

Vendor

Vendor Severity: LOW

CVSS v2

Risk Factor: Medium

Base Score: 4.9

Temporal Score: 3.6

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

CVSS Score Source: CVE-2026-68093

CVSS v3

Risk Factor: Medium

Base Score: 6.7

Temporal Score: 5.8

Vector: CVSS:3.0/AV:L/AC:H/PR:H/UI:N/S:C/C:L/I:L/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: 8/10/2026

Reference Information

CVE: CVE-2026-68093