Skip to main content

Linux Kernel CVE-2025-68801

HIGH
2026-01-13 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Information Disclosure Linux Red Hat Nvidia Suse
7.8
CVSS 3.1 · Vendor: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Share

Severity by source

Vendor (416baaa9-dc9f-4396-8d5f-8c081fb06d67) PRIMARY
7.8 HIGH
AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
vuln.today AI
5.2 MEDIUM

Local-only, requires CAP_NET_ADMIN (PR:H) and winning a hard-to-reproduce race (AC:H); primary observed impact is a kernel crash (A:H) with limited/uncertain C/I from UAF.

3.1 AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:L/A:H
4.0 AV:L/AC:H/AT:N/PR:H/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N
SUSE
6.7 MEDIUM
AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
Red Hat
5.6 MEDIUM
qualitative

Primary rating from Vendor (416baaa9-dc9f-4396-8d5f-8c081fb06d67).

CVSS VectorVendor: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Lifecycle Timeline

8
Analysis Updated
Jul 30, 2026 - 07:16 vuln.today
v4 (cvss_changed)
Analysis Updated
Jul 30, 2026 - 07:16 vuln.today
v3 (cvss_changed)
Analysis Updated
Jul 30, 2026 - 07:16 vuln.today
v2 (cvss_changed)
Re-analysis Queued
Jul 30, 2026 - 06:37 vuln.today
cvss_changed
CVSS changed
Jul 30, 2026 - 06:37 NVD
7.8 (HIGH)
Patch released
Mar 16, 2026 - 15:00 nvd
Patch available
Analysis Generated
Mar 12, 2026 - 21:54 vuln.today
CVE Published
Jan 13, 2026 - 16:16 nvd
N/A

DescriptionCVE.org

In the Linux kernel, the following vulnerability has been resolved:

mlxsw: spectrum_router: Fix neighbour use-after-free

We sometimes observe use-after-free when dereferencing a neighbour [1]. The problem seems to be that the driver stores a pointer to the neighbour, but without holding a reference on it. A reference is only taken when the neighbour is used by a nexthop.

Fix by simplifying the reference counting scheme. Always take a reference when storing a neighbour pointer in a neighbour entry. Avoid taking a referencing when the neighbour is used by a nexthop as the neighbour entry associated with the nexthop already holds a reference.

Tested by running the test that uncovered the problem over 300 times. Without this patch the problem was reproduced after a handful of iterations.

[1] BUG: KASAN: slab-use-after-free in mlxsw_sp_neigh_entry_update+0x2d4/0x310 Read of size 8 at addr ffff88817f8e3420 by task ip/3929

CPU: 3 UID: 0 PID: 3929 Comm: ip Not tainted 6.18.0-rc4-virtme-g36b21a067510 #3 PREEMPT(full) Hardware name: Nvidia SN5600/VMOD0013, BIOS 5.13 05/31/2023 Call Trace: <TASK> dump_stack_lvl+0x6f/0xa0 print_address_description.constprop.0+0x6e/0x300 print_report+0xfc/0x1fb kasan_report+0xe4/0x110 mlxsw_sp_neigh_entry_update+0x2d4/0x310 mlxsw_sp_router_rif_gone_sync+0x35f/0x510 mlxsw_sp_rif_destroy+0x1ea/0x730 mlxsw_sp_inetaddr_port_vlan_event+0xa1/0x1b0 __mlxsw_sp_inetaddr_lag_event+0xcc/0x130 __mlxsw_sp_inetaddr_event+0xf5/0x3c0 mlxsw_sp_router_netdevice_event+0x1015/0x1580 notifier_call_chain+0xcc/0x150 call_netdevice_notifiers_info+0x7e/0x100 __netdev_upper_dev_unlink+0x10b/0x210 netdev_upper_dev_unlink+0x79/0xa0 vrf_del_slave+0x18/0x50 do_set_master+0x146/0x7d0 do_setlink.isra.0+0x9a0/0x2880 rtnl_newlink+0x637/0xb20 rtnetlink_rcv_msg+0x6fe/0xb90 netlink_rcv_skb+0x123/0x380 netlink_unicast+0x4a3/0x770 netlink_sendmsg+0x75b/0xc90 __sock_sendmsg+0xbe/0x160 ____sys_sendmsg+0x5b2/0x7d0 ___sys_sendmsg+0xfd/0x180 __sys_sendmsg+0x124/0x1c0 do_syscall_64+0xbb/0xfd0 entry_SYSCALL_64_after_hwframe+0x4b/0x53 [...]

Allocated by task 109: kasan_save_stack+0x30/0x50 kasan_save_track+0x14/0x30 __kasan_kmalloc+0x7b/0x90 __kmalloc_noprof+0x2c1/0x790 neigh_alloc+0x6af/0x8f0 ___neigh_create+0x63/0xe90 mlxsw_sp_nexthop_neigh_init+0x430/0x7e0 mlxsw_sp_nexthop_type_init+0x212/0x960 mlxsw_sp_nexthop6_group_info_init.constprop.0+0x81f/0x1280 mlxsw_sp_nexthop6_group_get+0x392/0x6a0 mlxsw_sp_fib6_entry_create+0x46a/0xfd0 mlxsw_sp_router_fib6_replace+0x1ed/0x5f0 mlxsw_sp_router_fib6_event_work+0x10a/0x2a0 process_one_work+0xd57/0x1390 worker_thread+0x4d6/0xd40 kthread+0x355/0x5b0 ret_from_fork+0x1d4/0x270 ret_from_fork_asm+0x11/0x20

Freed by task 154: kasan_save_stack+0x30/0x50 kasan_save_track+0x14/0x30 __kasan_save_free_info+0x3b/0x60 __kasan_slab_free+0x43/0x70 kmem_cache_free_bulk.part.0+0x1eb/0x5e0 kvfree_rcu_bulk+0x1f2/0x260 kfree_rcu_work+0x130/0x1b0 process_one_work+0xd57/0x1390 worker_thread+0x4d6/0xd40 kthread+0x355/0x5b0 ret_from_fork+0x1d4/0x270 ret_from_fork_asm+0x11/0x20

Last potentially related work creation: kasan_save_stack+0x30/0x50 kasan_record_aux_stack+0x8c/0xa0 kvfree_call_rcu+0x93/0x5b0 mlxsw_sp_router_neigh_event_work+0x67d/0x860 process_one_work+0xd57/0x1390 worker_thread+0x4d6/0xd40 kthread+0x355/0x5b0 ret_from_fork+0x1d4/0x270 ret_from_fork_asm+0x11/0x20

AnalysisAI

Local privilege-holder-triggered use-after-free in the Linux kernel's mlxsw Spectrum switch driver (drivers/net/ethernet/mellanox/mlxsw) lets a network-admin operation on Nvidia/Mellanox Spectrum ASIC hardware dereference a freed neighbour object during RIF teardown. The driver cached a neighbour pointer without holding a reference, so freeing the neighbour (e.g. while removing a device from a VRF) leaves a dangling pointer that mlxsw_sp_neigh_entry_update() reads, corrupting kernel memory. CVSS is 7.8 (local, low privilege in the automated NVD scoring) but EPSS is only 0.05% (16th percentile) and there is no public exploit or CISA KEV listing - the flaw was found via an internal stress test, not observed attacks.

Technical ContextAI

The affected component is mlxsw_sp (spectrum_router), the in-tree driver for Nvidia/Mellanox Spectrum switch ASICs used in data-center switches. The kernel's neighbouring subsystem (neigh_alloc/___neigh_create) manages ARP/NDP neighbour entries that are freed via RCU (kvfree_rcu / kfree_rcu_work). mlxsw stored a raw pointer to a struct neighbour inside its own neighbour entry but only took a refcount when the neighbour backed a nexthop; when no nexthop held it, the neighbour could be freed while the driver still referenced it. This is a classic use-after-free (CWE-416, listed as N/A in the input) - a lifetime/reference-counting bug where object ownership is not enforced by a held reference. The KASAN 'slab-use-after-free' report shows the read occurring in mlxsw_sp_neigh_entry_update during mlxsw_sp_router_rif_gone_sync, reached from an rtnetlink netdevice-unlink event (vrf_del_slave → do_set_master).

Affected ProductsAI

The Linux kernel's mlxsw Spectrum driver is affected on builds where CONFIG for mlxsw_spectrum is enabled and Mellanox/Nvidia Spectrum switch ASIC hardware is present. No explicit fixed-version numbers or CPE strings were provided in the input; the seven git.kernel.org/stable commits (4a3c569, 675c5ae, 8b0e697, 9e0a0d9, a2dfe67, c437fbf, ed8141b) indicate the fix was backported across multiple stable branches, and the reproducer was seen on 6.18.0-rc4. Canonical has published USN-8096-1 (https://ubuntu.com/security/notices/USN-8096-1) covering the affected Ubuntu kernels, and VulDB tracks it at https://vuldb.com/?id.340643. Exact affected version ranges should be confirmed against the individual stable-branch commits and the USN.

RemediationAI

Vendor-released patch: apply the kernel update that includes the mlxsw spectrum_router neighbour reference-counting fix - Ubuntu users should update to the fixed kernel per USN-8096-1 (https://ubuntu.com/security/notices/USN-8096-1), and users building from source should pick up the corresponding stable commits (e.g. https://git.kernel.org/stable/c/4a3c569005f42ab5e5b2ad637132a33bf102cc08 and the six sibling backports). Reboot into the patched kernel to load the corrected driver. Because there is no runtime toggle for this code path, the practical compensating control where patching must be delayed is to restrict CAP_NET_ADMIN and limit who can reconfigure switch interfaces, VRF membership, and LAG/upper-device links on affected mlxsw hosts - the trade-off is that this constrains legitimate network-operations tooling; on hosts that do not use Mellanox Spectrum switching, unloading the mlxsw_spectrum module removes exposure entirely at the cost of disabling that hardware's offload.

More in Nvidia

View all
CVE-2017-14491 CRITICAL POC
9.8 Oct 04

Heap-based buffer overflow in dnsmasq before 2.78 allows remote attackers to cause a denial of service (crash) or execut
CVE-2018-3639 MEDIUM POC
5.5 May 22

Systems with microprocessors utilizing speculative execution and speculative execution of memory reads before the addres
CVE-2016-1741 CRITICAL POC
9.8 Mar 24

The NVIDIA driver in the Graphics Drivers subsystem in Apple OS X before 10.11.4 allows attackers to execute arbitrary c
CVE-2013-0109 HIGH POC
7.2 Apr 08

The NVIDIA driver before 307.78, and Release 310 before 311.00, in the NVIDIA Display Driver service on Windows does not
CVE-2019-5684 CRITICAL POC
10.0 Aug 06

NVIDIA Windows GPU Display Driver (all versions) contains a vulnerability in DirectX drivers, in which a specially craft
CVE-2026-24207 CRITICAL POC
9.8 May 20

Authentication bypass in NVIDIA Triton Inference Server allows unauthenticated remote attackers to reach protected funct
CVE-2019-5685 CRITICAL POC
9.8 Aug 06

NVIDIA Windows GPU Display Driver (all versions) contains a vulnerability in DirectX drivers, in which a specially craft
CVE-2025-23359 HIGH POC
8.3 Feb 12

NVIDIA Container Toolkit for Linux contains a Time-of-Check Time-of-Use (TOCTOU) vulnerability when used with default co
CVE-2016-8812 HIGH POC
8.8 Nov 08

For the NVIDIA Quadro, NVS, and GeForce products, NVIDIA GeForce Experience R340 before GFE 2.11.4.125 and R375 before G
CVE-2017-1000251 HIGH POC
8.0 Sep 12

The native Bluetooth stack in the Linux Kernel (BlueZ), starting at the Linux kernel version 2.6.32 and up to and includ
CVE-2016-1861 HIGH POC
7.8 Jun 19

The NVIDIA Graphics Drivers subsystem in Apple OS X before 10.11.5 allows attackers to execute arbitrary code in a privi
CVE-2024-0132 HIGH POC
8.3 Sep 26

NVIDIA Container Toolkit 1.16.1 or earlier contains a Time-of-check Time-of-Use (TOCTOU) vulnerability when used with de

Same technique Information Disclosure

View all
CVE-2019-2725 CRITICAL POC
9.8
CVE-2021-34523 CRITICAL POC
9.0
CVE-2013-2251 CRITICAL POC
9.8
CVE-2017-5638 CRITICAL POC
9.8
CVE-2025-24813 CRITICAL POC
9.8
CVE-2015-1701 HIGH POC
7.8
CVE-2017-0147 HIGH POC
7.5
CVE-2014-6324 HIGH POC
8.8

Vendor StatusVendor

SUSE

Severity: Moderate
Product Status
Container suse/sl-micro/6.0/baremetal-os-container:latest Container suse/sl-micro/6.0/toolbox:latest Affected
Container suse/sl-micro/6.0/base-os-container:2.1.3-7.95 Image SL-Micro Image SLE-Micro Image SLE-Micro-Azure Image SLE-Micro-BYOS Image SLE-Micro-BYOS-Azure Image SLE-Micro-BYOS-EC2 Image SLE-Micro-BYOS-GCE Image SLE-Micro-EC2 Image SLE-Micro-GCE Affected
Container suse/sl-micro/6.0/kvm-os-container:2.1.3-6.115 Affected
Container suse/sl-micro/6.0/rt-os-container:2.1.3-7.146 Affected
Container suse/sl-micro/6.1/base-os-container:2.2.1-5.80 Image SL-Micro-Azure Image SL-Micro-BYOS-Azure Image SL-Micro-BYOS-EC2 Image SL-Micro-BYOS-GCE Image SL-Micro-EC2 Image SUSE-Multi-Linux-Manager-Proxy-BYOS-Azure Image SUSE-Multi-Linux-Manager-Proxy-BYOS-EC2 Image SUSE-Multi-Linux-Manager-Proxy-BYOS-GCE Image SUSE-Multi-Linux-Manager-Server-Azure-llc Image SUSE-Multi-Linux-Manager-Server-Azure-ltd Image SUSE-Multi-Linux-Manager-Server-BYOS-Azure Image SUSE-Multi-Linux-Manager-Server-BYOS-EC2 Image SUSE-Multi-Linux-Manager-Server-BYOS-GCE Image SUSE-Multi-Linux-Manager-Server-EC2-llc Image SUSE-Multi-Linux-Manager-Server-EC2-ltd Affected

Share

CVE-2025-68801 vulnerability details – vuln.today
Back

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy