CVE-2026-23381
net: bridge: fix nd_tbl NULL dereference when IPv6 is disabled
Description
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.
INFO
Published Date :
March 25, 2026, 11:16 a.m.
Last Modified :
April 24, 2026, 6:41 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update the Linux kernel to a patched version.
- Replace IS_ENABLED(IPV6) with ipv6_mod_enabled() callers.
- Disable NS/NA suppression when IPv6 is disabled.
Public PoC/Exploit Available at Github
CVE-2026-23381 has a 1 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-23381.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-23381 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
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stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-23381
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
DSA and DLA for Debian last 14 days
Python
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-23381 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-23381 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Apr. 24, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-476 Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:4.15:-:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.19 up to (excluding) 6.19.7 *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:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.13 up to (excluding) 6.18.17 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.2 up to (excluding) 6.6.130 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.7 up to (excluding) 6.12.77 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.11 up to (excluding) 5.15.203 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.16 up to (excluding) 6.1.167 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 4.15.1 up to (excluding) 5.10.253 Added Reference Type kernel.org: https://git.kernel.org/stable/c/20ef5c25422f97dd09d751e5ae6c18406cdc78e6 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/33dec6f10777d5a8f71c0a200f690da5ae3c2e55 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/7a894eb5de246d79f13105c55a67381039a24d44 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/a12cdaa3375f0bd3c8f4e564be7c143529abfe5b Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/a5c56e65b685360dd3f2278aeff8c21061feb665 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/a9d712ccfeef737c0e700a4b5b98f310e07b6b60 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/aa73deb3b6b730ec280d45b3f423bfa9e17bc122 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/e5e890630533bdc15b26a34bb8e7ef539bdf1322 Types: Patch -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Apr. 18, 2026
Action Type Old Value New Value Added Reference https://git.kernel.org/stable/c/a5c56e65b685360dd3f2278aeff8c21061feb665 Added Reference https://git.kernel.org/stable/c/a9d712ccfeef737c0e700a4b5b98f310e07b6b60 -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Mar. 25, 2026
Action Type Old Value New Value Added Description 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. Added Reference https://git.kernel.org/stable/c/20ef5c25422f97dd09d751e5ae6c18406cdc78e6 Added Reference https://git.kernel.org/stable/c/33dec6f10777d5a8f71c0a200f690da5ae3c2e55 Added Reference https://git.kernel.org/stable/c/7a894eb5de246d79f13105c55a67381039a24d44 Added Reference https://git.kernel.org/stable/c/a12cdaa3375f0bd3c8f4e564be7c143529abfe5b Added Reference https://git.kernel.org/stable/c/aa73deb3b6b730ec280d45b3f423bfa9e17bc122 Added Reference https://git.kernel.org/stable/c/e5e890630533bdc15b26a34bb8e7ef539bdf1322