CVE-2026-23381

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Source
https://cve.org/CVERecord?id=CVE-2026-23381
Import Source
https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-23381.json
JSON Data
https://api.test.osv.dev/v1/vulns/CVE-2026-23381
Downstream
Related
Published
2026-03-25T10:28:00Z
Modified
2026-08-12T03:30:09Z
Summary
net: bridge: fix nd_tbl NULL dereference when IPv6 is disabled
Details

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: ? 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.

Database specific 
{
    "cna_assigner":  "Linux",
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23381.json"
}
References

Affected packages

Git / git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Affected ranges

Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
ed842faeb2bd49256f00485402f3113205f91d30
Fixed
a9d712ccfeef737c0e700a4b5b98f310e07b6b60
Fixed
a5c56e65b685360dd3f2278aeff8c21061feb665
Fixed
7a894eb5de246d79f13105c55a67381039a24d44
Fixed
a12cdaa3375f0bd3c8f4e564be7c143529abfe5b
Fixed
aa73deb3b6b730ec280d45b3f423bfa9e17bc122
Fixed
33dec6f10777d5a8f71c0a200f690da5ae3c2e55
Fixed
20ef5c25422f97dd09d751e5ae6c18406cdc78e6
Fixed
e5e890630533bdc15b26a34bb8e7ef539bdf1322

Database specific

source 
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-23381.json"

Linux / Kernel

Package

Name
Kernel

Affected ranges

Type
ECOSYSTEM
Events
Introduced
4.15.0
Fixed
5.10.253
Type
ECOSYSTEM
Events
Introduced
5.11.0
Fixed
5.15.203
Type
ECOSYSTEM
Events
Introduced
5.16.0
Fixed
6.1.167
Type
ECOSYSTEM
Events
Introduced
6.2.0
Fixed
6.6.130
Type
ECOSYSTEM
Events
Introduced
6.7.0
Fixed
6.12.77
Type
ECOSYSTEM
Events
Introduced
6.13.0
Fixed
6.18.17
Type
ECOSYSTEM
Events
Introduced
6.19.0
Fixed
6.19.7

Database specific

source 
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-23381.json"