Google: sys-kernel/cchost-kernel-6_12, sys-kernel/cchost-kernel-6_18, sys-kernel/csql-kernel-6_12, sys-kernel/csql-kernel-6_18, sys-kernel/lakitu-kernel-6_12, sys-kernel/lakitu-kernel-6_18, sys-kernel/lakitu-nc-kernel-6_12, sys-kernel/lakitu-nc-kernel-6_18: security update to 19804.0.0

high Tenable Self-Hosted Container Security Plugin ID 470971

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: bpf: Fix use-after-free in
arena_vm_close on fork arena_vm_open() only bumps vml->mmap_count but never registers the child VMA in
arena->vma_list. The vml->vma always points at the parent VMA, so after parent munmap the pointer dangles.
If the child then calls bpf_arena_free_pages(), zap_pages() reads the stale vml->vma triggering use-after-
free. Fix this by preventing the arena VMA from being inherited across fork with VM_DONTCOPY, and
preventing VMA splits via the may_split callback. Also reject mremap with a .mremap callback returning
-EINVAL. A same-size mremap(MREMAP_FIXED) on the full arena VMA reaches copy_vma() through the following
path: check_prep_vma() - returns 0 early: new_len == old_len skips VM_DONTEXPAND check prep_move_vma() -
vm_start == old_addr and vm_end == old_addr + old_len so may_split is never called move_vma()
copy_vma_and_data() copy_vma() vm_area_dup() - copies vm_private_data (vml pointer) vm_ops->open() - bumps
vml->mmap_count vm_ops->mremap() - returns -EINVAL, rollback unmaps new VMA The refcount ensures the
rollback's arena_vm_close does not free the vml shared with the original VMA. (CVE-2026-45837)

Solution

Update the sys-kernel/cchost-kernel-6_12 library and its related packages to version 19804.0.0 or later.

Plugin Details

Severity: High

ID: 470971

Version: Revision 1.3

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: 58.01

Vendor

Vendor Severity: HIGH

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-2026-45837

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: 5/26/2026

Reference Information

CVE: CVE-2026-45837

Detections

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