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 19506.448.8

high Tenable Cloud Security Plugin ID 472243

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: Update x2APIC MSR intercepts
if AVIC is inhibited while L2 is active Always update x2APIC MSR intercepts for L1 when AVIC is
deactivated, even if L2 is active and KVM is using a separate MSR bitmap to run L2. If AVIC is fully
enabled prior to running L2, and is then inhibited while L2 is active (for a VM-scoped inhibit), then KVM
will run L1 with AVIC disabled, but with x2APIC MSR intercepts disabled, i.e. will allow L1 to read most
of the host's APIC state, send arbitrary interrupts, change task priority, and ultimately trivially DoS
the host. E.g. sending a self-IPI in L1 on HYPERV_REENLIGHTENMENT_VECTOR, 0xee, with CONFIG_HYPERV=n in
the host kernel as a "safe" PoC, yields: Spurious interrupt (vector 0xee) on CPU#425. Acked And hacking
KVM to abuse kvm_set_posted_intr_wakeup_handler() to register a handler and WARN on
POSTED_INTR_WAKEUP_VECTOR yields: ------------[ cut here ]------------ WARNING:
arch/x86/kvm/svm/svm.c:5594 at pi_wakeup_handler+0x9/0x10 [kvm_amd], CPU#156: nested_x2apic_t/316940 CPU:
156 UID: 0 PID: 316940 Comm: nested_x2apic_t Tainted: G S U Tainted: [S]=CPU_OUT_OF_SPEC, [U]=USER
Hardware name: Google Astoria-Turin/astoria, BIOS 0.20260209.0-0 02/09/2026 RIP:
0010:pi_wakeup_handler+0x9/0x10 [kvm_amd] Call Trace: <IRQ> sysvec_kvm_posted_intr_wakeup_ipi+0x64/0x80
</IRQ> <TASK> asm_sysvec_kvm_posted_intr_wakeup_ipi+0x1a/0x20 RIP: 0010:vcpu_run+0x1430/0x1e40 [kvm]
kvm_arch_vcpu_ioctl_run+0x2c1/0x600 [kvm] kvm_vcpu_ioctl+0x580/0x6b0 [kvm] __se_sys_ioctl+0x6d/0xb0
do_syscall_64+0x10a/0x480 entry_SYSCALL_64_after_hwframe+0x4b/0x53 RIP: 0033:0x46ff4b </TASK> ---[ end
trace 0000000000000000 ]--- (CVE-2026-74516)

Solution

Update the sys-kernel/cchost-kernel-6_12 library and its related packages to version 19506.448.8 or later.

Plugin Details

Severity: High

ID: 472243

Version: Revision 1.1

Type: Local

Family: Google COS Security Checks

Published: 10/3/2026

Updated: 10/3/2026

Risk Information

VPR

Risk Factor: Medium

Score: 5

Percentile: 93.3

Vendor

Vendor Severity: LOW

CVSS v2

Risk Factor: Medium

Base Score: 6.5

Temporal Score: 4.8

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

CVSS Score Source: CVE-2026-74516

CVSS v3

Risk Factor: High

Base Score: 8.2

Temporal Score: 7.1

Vector: CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:C/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: 8/11/2026

Reference Information

CVE: CVE-2026-74516

Detections

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