CVE-2026-23293 net: vxlan: fix nd_tbl NULL dereference when IPv6 is disabled
A local attacker can cause a kernel crash by injecting IPv6 packets into a VXLAN interface when IPv6 is disabled via boot parameter.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-23293?
CVE-2026-23293 is a medium-severity vulnerability in Linux kernel, published on 25 Mar 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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 because VXLAN can be built-in even when IPv6 is built as a module.
Weakness: CWE-476
Which versions are affected by CVE-2026-23293?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-23293?
Apply the vendor's patch.
Is CVE-2026-23293 being exploited?
There is no known exploitation of CVE-2026-23293 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-80723, BELL-CVE-2026-23293, DEBIAN-CVE-2026-23293, GHSA-4mrh-9qq5-26w5, ROOT-OS-DEBIAN-11-CVE-2026-23293, ROOT-OS-DEBIAN-12-CVE-2026-23293 and 4 more.