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

high Tenable Cloud Security Plugin ID 475477

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: vxlan: mdb: Fix use-after-free in
vxlan_mdb_flush() vxlan_mdb_flush() iterates over the MDB entries using hlist_for_each_entry_safe(), which
only tolerates the removal of the current entry. Contrary to the comment above the loop, the removal of an
entry can trigger the removal of another entry. Flushing the remotes of a (*, G) entry also removes the
(S, G) entries that were created for its source list, once they are left without remotes:
vxlan_mdb_remotes_flush() -> vxlan_mdb_remote_del() -> vxlan_mdb_remote_srcs_del() ->
vxlan_mdb_remote_src_del() -> vxlan_mdb_remote_src_fwd_del() -> __vxlan_mdb_del() -> vxlan_mdb_entry_put()
Such an entry can be located after the (*, G) entry in the list, as vxlan_mdb_entry_get() returns an
existing entry without moving it to the head of the list. This order is obtained by adding the (S, G)
entry before the (*, G) entry, the latter with NLM_F_REPLACE, as the addition of the source otherwise
fails with -EEXIST. The (S, G) entry is then the entry saved by hlist_for_each_entry_safe() and it is
freed while the (*, G) entry is processed. The next iteration calls hlist_del() on it again, writing
LIST_POISON1 to LIST_POISON2 [1]. Besides device deletion, the flush is also reachable from RTM_DELMDB
with NLM_F_BULK. Fix by re-reading the next entry after the remotes were flushed. The current entry cannot
be removed by this flush, as source lists can only be configured on (*, G) entries and the removed entries
are (S, G) entries. It is therefore still linked and its next pointer reflects the removals. [1] BUG:
KASAN: wild-memory-access in vxlan_mdb_entry_put.part.0+0x328/0x588 Write of size 8 at addr
dead000000000122 by task ip/327 CPU: 3 UID: 1000 PID: 327 Comm: ip Not tainted 7.2.0-rc7 #2 PREEMPT Call
trace: vxlan_mdb_entry_put.part.0+0x328/0x588 vxlan_mdb_flush+0x1d8/0x25c vxlan_mdb_fini+0x8c/0x100
vxlan_uninit+0x1c/0x7c unregister_netdevice_many_notify+0x954/0xd4c rtnl_dellink+0x210/0x530
rtnetlink_rcv_msg+0x434/0x4d0 netlink_rcv_skb+0xc4/0x204 rtnetlink_rcv+0x18/0x24
netlink_unicast+0x4b8/0x548 netlink_sendmsg+0x29c/0x560 ____sys_sendmsg+0x390/0x3ec
___sys_sendmsg+0x114/0x188 __sys_sendmsg+0xf0/0x178 __arm64_sys_sendmsg+0x48/0x60
invoke_syscall.constprop.0+0x58/0x180 el0_svc_common.constprop.0+0x74/0x140 do_el0_svc+0x30/0x40
el0_svc+0x38/0x98 el0t_64_sync_handler+0xa0/0xe4 el0t_64_sync+0x198/0x19c (CVE-2026-93250)

Solution

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

Plugin Details

Severity: High

ID: 475477

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: 6.9

Percentile: 96.51

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-2026-93250

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: 9/24/2026

Reference Information

CVE: CVE-2026-93250

Detections

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