CVE-2026-23293

/// Technical description

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

net: vxlan: 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. If an IPv6 packet is injected into the interface,

route_shortcircuit() is called and a NULL pointer dereference happens on

neigh_lookup().

BUG: kernel NULL pointer dereference, address: 0000000000000380

Oops: Oops: 0000 [#1] SMP NOPTI

[...]

RIP: 0010:neigh_lookup+0x20/0x270

[...]

Call Trace:

<TASK>

vxlan_xmit+0x638/0x1ef0 [vxlan]

dev_hard_start_xmit+0x9e/0x2e0

__dev_queue_xmit+0xbee/0x14e0

packet_sendmsg+0x116f/0x1930

__sys_sendto+0x1f5/0x200

__x64_sys_sendto+0x24/0x30

do_syscall_64+0x12f/0x1590

entry_SYSCALL_64_after_hwframe+0x76/0x7e

Fix this by adding an early check on route_shortcircuit() when protocol

is ETH_P_IPV6. Note that ipv6_mod_enabled() cannot be used here bec

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References