CVE-2026-23381

  1. OpenCVE
  2. Vulnerabilities (CVE)
  3. CVE-2026-23381
In the Linux kernel, the following vulnerability has been resolved: net: bridge: fix nd_tbl NULL dereference when IPv6 is disabled When booting with the 'ipv6.disable=1' parameter, the nd_tbl is never initialized because inet6_init() exits before ndisc_init() is called which initializes it. Then, if neigh_suppress is enabled and an ICMPv6 Neighbor Discovery packet reaches the bridge, br_do_suppress_nd() will dereference ipv6_stub->nd_tbl which is NULL, passing it to neigh_lookup(). This causes a kernel NULL pointer dereference. BUG: kernel NULL pointer dereference, address: 0000000000000268 Oops: 0000 [#1] PREEMPT SMP NOPTI [...] RIP: 0010:neigh_lookup+0x16/0xe0 [...] Call Trace: <IRQ> ? neigh_lookup+0x16/0xe0 br_do_suppress_nd+0x160/0x290 [bridge] br_handle_frame_finish+0x500/0x620 [bridge] br_handle_frame+0x353/0x440 [bridge] __netif_receive_skb_core.constprop.0+0x298/0x1110 __netif_receive_skb_one_core+0x3d/0xa0 process_backlog+0xa0/0x140 __napi_poll+0x2c/0x170 net_rx_action+0x2c4/0x3a0 handle_softirqs+0xd0/0x270 do_softirq+0x3f/0x60 Fix this by replacing IS_ENABLED(IPV6) call with ipv6_mod_enabled() in the callers. This is in essence disabling NS/NA suppression when IPv6 is disabled.

5.5 /10

CVSS v3 : MEDIUM

V3 Legend

Vector :

Exploitability : 1.8 / Impact : 3.6

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References
Link Resource
https://git.kernel.org/stable/c/20ef5c25422f97dd09d751e5ae6c18406cdc78e6 Patch
https://git.kernel.org/stable/c/33dec6f10777d5a8f71c0a200f690da5ae3c2e55 Patch
https://git.kernel.org/stable/c/7a894eb5de246d79f13105c55a67381039a24d44 Patch
https://git.kernel.org/stable/c/a12cdaa3375f0bd3c8f4e564be7c143529abfe5b Patch
https://git.kernel.org/stable/c/a5c56e65b685360dd3f2278aeff8c21061feb665 Patch
https://git.kernel.org/stable/c/a9d712ccfeef737c0e700a4b5b98f310e07b6b60 Patch
https://git.kernel.org/stable/c/aa73deb3b6b730ec280d45b3f423bfa9e17bc122 Patch
https://git.kernel.org/stable/c/e5e890630533bdc15b26a34bb8e7ef539bdf1322 Patch
Configurations

Configuration 1 (hide)

OR cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:4.15:-:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc7:*:*:*:*:*:*
History

24 Apr 2026, 18:41

Type Values Removed Values Added
References () https://git.kernel.org/stable/c/20ef5c25422f97dd09d751e5ae6c18406cdc78e6 - () https://git.kernel.org/stable/c/20ef5c25422f97dd09d751e5ae6c18406cdc78e6 - Patch
References () https://git.kernel.org/stable/c/33dec6f10777d5a8f71c0a200f690da5ae3c2e55 - () https://git.kernel.org/stable/c/33dec6f10777d5a8f71c0a200f690da5ae3c2e55 - Patch
References () https://git.kernel.org/stable/c/7a894eb5de246d79f13105c55a67381039a24d44 - () https://git.kernel.org/stable/c/7a894eb5de246d79f13105c55a67381039a24d44 - Patch
References () https://git.kernel.org/stable/c/a12cdaa3375f0bd3c8f4e564be7c143529abfe5b - () https://git.kernel.org/stable/c/a12cdaa3375f0bd3c8f4e564be7c143529abfe5b - Patch
References () https://git.kernel.org/stable/c/a5c56e65b685360dd3f2278aeff8c21061feb665 - () https://git.kernel.org/stable/c/a5c56e65b685360dd3f2278aeff8c21061feb665 - Patch
References () https://git.kernel.org/stable/c/a9d712ccfeef737c0e700a4b5b98f310e07b6b60 - () https://git.kernel.org/stable/c/a9d712ccfeef737c0e700a4b5b98f310e07b6b60 - Patch
References () https://git.kernel.org/stable/c/aa73deb3b6b730ec280d45b3f423bfa9e17bc122 - () https://git.kernel.org/stable/c/aa73deb3b6b730ec280d45b3f423bfa9e17bc122 - Patch
References () https://git.kernel.org/stable/c/e5e890630533bdc15b26a34bb8e7ef539bdf1322 - () https://git.kernel.org/stable/c/e5e890630533bdc15b26a34bb8e7ef539bdf1322 - Patch
CVSS v2 : unknown
v3 : unknown 		v2 : unknown
v3 : 5.5
CPE cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc7:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:4.15:-:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*
CWE CWE-476
First Time Linux
Linux linux Kernel

18 Apr 2026, 09:16

Type Values Removed Values Added
References
  • () https://git.kernel.org/stable/c/a5c56e65b685360dd3f2278aeff8c21061feb665 -
  • () https://git.kernel.org/stable/c/a9d712ccfeef737c0e700a4b5b98f310e07b6b60 -
Summary
  • (es) En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta: net: bridge: corrige la desreferencia NULL de nd_tbl cuando IPv6 está deshabilitado Al arrancar con el parámetro 'ipv6.disable=1', el nd_tbl nunca se inicializa porque inet6_init() sale antes de que se llame a ndisc_init(), que es quien lo inicializa. Luego, si neigh_suppress está habilitado y un paquete ICMPv6 Neighbor Discovery llega al puente, br_do_suppress_nd() desreferenciará ipv6_stub-&gt;nd_tbl, que es NULL, pasándolo a neigh_lookup(). Esto causa una desreferencia de puntero NULL del kernel. BUG: desreferencia de puntero NULL del kernel, dirección: 0000000000000268 Oops: 0000 [#1] PREEMPT SMP NOPTI [...] RIP: 0010:neigh_lookup+0x16/0xe0 [...] Rastro de Llamada: ? neigh_lookup+0x16/0xe0 br_do_suppress_nd+0x160/0x290 [bridge] br_handle_frame_finish+0x500/0x620 [bridge] br_handle_frame+0x353/0x440 [bridge] __netif_receive_skb_core.constprop.0+0x298/0x1110 __netif_receive_skb_one_core+0x3d/0xa0 process_backlog+0xa0/0x140 __napi_poll+0x2c/0x170 net_rx_action+0x2c4/0x3a0 handle_softirqs+0xd0/0x270 do_softirq+0x3f/0x60 Soluciona esto reemplazando la llamada a IS_ENABLED(IPV6) con ipv6_mod_enabled() en los llamadores. Esto es, en esencia, deshabilitar la supresión de NS/NA cuando IPv6 está deshabilitado.

25 Mar 2026, 11:16

Type Values Removed Values Added
New CVE
Information

Published : 2026-03-25 11:16

Updated : 2026-04-24 18:41

NVD link : CVE-2026-23381

Mitre link : CVE-2026-23381

CVE.ORG link : CVE-2026-23381

JSON object : View

Products Affected

linux

  • linux_kernel
CWE
CWE-476

NULL Pointer Dereference