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 19999.44.106

critical Tenable Cloud Security Plugin ID 475335

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: net: ipv6: Fix UDP length overflow
with PMTU discover and big MTU This commit bounds cork->base.fragsize to IP6_MAX_MTU for UDP sockets to
avoid a possible overflow of UDP length that triggers a WARN in udp_set_len_short when setsockopt
IPV6_MTU_DISCOVER is set to IPV6_PMTUDISC_DO or IPV6_PMTUDISC_PROBE, and a large packet is sent over a
netdev with an unusually large MTU. Steps to reproduce (included in the new selftest): 1. Set device MTU
bigger than IP6_MAX_MTU. cork->base.fragsize will be set to that MTU in ip6_setup_cork. 2. Set
IPV6_MTU_DISCOVER to IPV6_PMTUDISC_PROBE or IPV6_PMTUDISC_DO. It lets maxnonfragsize be set to device MTU
(cork->fragsize) in __ip6_append_data, rather than to IP6_MAX_MTU. 3. Send 65528 bytes of payload (+8
bytes of UDP header, +40 bytes of IPv6 header). Device MTU allows it (it's only one byte bigger than
IP6_MAX_MTU, and the device MTU is bigger than that). 4. The UDP length in the built packet is 65536,
which overflows the 16-bit length field and triggers the WARN in udp_set_len_short. To avoid breaking
sending UDP jumbograms over raw IPv6 sockets, limit the change to UDP sockets only. The original overflow
bug with IPv6 and IPV6_PMTUDISC_DO seems to predate git history (verified reproduction on 2.6.21), was
fixed later, and then reappeared in commit 427faee167bc ("net: ipv6: introduce
ip6_dst_mtu_maybe_forward"), which is chosen as the Fixes tag here. The overflow with IPV6_PMTUDISC_PROBE
reproduces since its introduction in commit 628a5c561890 ("[INET]: Add IP(V6)_PMTUDISC_RPOBE").
(CVE-2026-97984)

Solution

Update the sys-kernel/cchost-kernel-6_12 library and its related packages to version 19999.44.106 or later.

Plugin Details

Severity: Critical

ID: 475335

Version: Revision 1.1

Type: Local

Family: Google COS Security Checks

Published: 10/16/2026

Updated: 10/16/2026

Risk Information

VPR

Risk Factor: Medium

Score: 4.3

Percentile: 53.43

Vendor

Vendor Severity: LOW

CVSS v2

Risk Factor: High

Base Score: 7.5

Temporal Score: 5.5

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

CVSS Score Source: CVE-2026-97984

CVSS v3

Risk Factor: Critical

Base Score: 9.1

Temporal Score: 7.9

Vector: CVSS:3.0/AV:N/AC:L/PR:N/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: 9/25/2026

Reference Information

CVE: CVE-2026-97984

Detections

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