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 20085.0.0

high Tenable Self-Hosted Container Security Plugin ID 471356

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/core: Fix group leader use-after-
free after sibling detach perf_group_detach() handles leader and sibling detach differently. When the
group leader is detached, all siblings are promoted to singleton events and their group_leader pointer is
reset to themselves. When a sibling is detached, it is removed from the leader's sibling_list, but its
group_leader pointer is left pointing at the old leader. That is harmless when the sibling is being closed
and freed immediately, as in the DETACH_DEAD path. It is not safe when the sibling is detached but kept
alive, such as during CPU hotplug with DETACH_GROUP. In that case the sibling is removed from the context,
while its file descriptor can still keep it alive. A typical failing sequence is: - A group contains
leader L and sibling S. - CPU hot-unplug detaches S with DETACH_GROUP, removing it from L->sibling_list
but leaving S->group_leader == L. - L is later closed and freed. - A PERF_IOC_FLAG_GROUP ioctl on S
follows S->group_leader and dereferences the freed leader. This was reproduced by running the perf event
fuzzer, CPU hotplug, and a stress workload concurrently: Unable to handle kernel paging request at virtual
address 006b6b6b6b6b6cdb CPU: 2 PID: 12489 Comm: perf_fuzzer 6.18.7 PREEMPT pc : perf_ioctl+0x34c/0xc68
x20: ffffff89a3fa2c70 x8 : 6b6b6b6b6b6b6b6b Code: 943c4a0e 340047a0 f9404a94 f9411e88 (f940b908) Call
trace: perf_ioctl+0x34c/0xc68 (P) __arm64_sys_ioctl+0xa0/0xf4 invoke_syscall+0x58/0xe4
el0_svc_common+0xa8/0xdc do_el0_svc+0x1c/0x28 el0_svc+0x40/0xc0 el0t_64_sync_handler+0x68/0xdc
el0t_64_sync+0x1c4/0x1c8 The fault happened in perf_ioctl(), where perf_event_for_each() follows the stale
group_leader pointer and perf_event_for_each_child() then dereferences the freed leader's context. Fix the
use-after-free by promoting the detached sibling to a singleton. Also fix __event_disable() cgroup
accounting and event state change. (CVE-2026-74637)

Solution

Update the sys-kernel/cchost-kernel-6_18 library and its related packages to version 20085.0.0 or later.

Plugin Details

Severity: High

ID: 471356

Version: Revision 1.2

Type: Local

Family: Google COS Security Checks

Published: 10/3/2026

Updated: 10/3/2026

Supported Sensors: Tenable Cloud Security, Tenable Self-Hosted Container Security

Risk Information

VPR

Risk Factor: Medium

Score: 4.9

Percentile: 58.15

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-2026-74637

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: 8/22/2026

Reference Information

CVE: CVE-2026-74637

Detections

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