CVE-2026-45846 bareudp: fix NULL pointer dereference in bareudp_fill_metadata_dst()
A NULL pointer dereference in the Linux kernel bareudp driver allows local attackers to cause a system crash by triggering a specific network path while the device is down.
- 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-2026-45846?
CVE-2026-45846 is a medium-severity vulnerability in Linux kernel, published on 27 May 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:
bareudp: fix NULL pointer dereference in bareudp_fill_metadata_dst()
bareudp_fill_metadata_dst() passes bareudp->sock to udp_tunnel6_dst_lookup() in the IPv6 path without a NULL check. The socket is only created in bareudp_open() and NULLed in bareudp_stop(), so calling this function while the device is down triggers a NULL dereference via sock->sk.
BUG: kernel NULL pointer dereference, address: 0000000000000018 RIP: 0010:udp_tunnel6_dst_lookup (net/ipv6/ip6_udp_tunnel.c:160) Call Trace: <TASK> bareudp_fill_metadata_dst (drivers/net/bareudp.c:532) do_execute_actions (net/openvswitch/actions.c:901) ovs_execute_actions (net/openvswitch/actions.c:1589) ovs_packet_cmd_execute (net/openvswitch/datapath.c:700) genl_family_rcv_msg_doit (net/netlink/genetlink.c:1114) genl_rcv_msg (net/netlink/genetlink.c:1209) netlink_rcv_skb (net/netlink/af_netlink.c:2550) </TASK>
Add a NULL check returning -ESHUTDOWN, consistent with the xmit paths in the same driver.
Weakness: CWE-476
Which versions are affected by CVE-2026-45846?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-45846?
Apply the vendor's patch.
Is CVE-2026-45846 being exploited?
There is no known exploitation of CVE-2026-45846 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-88773, BELL-CVE-2026-45846, DEBIAN-CVE-2026-45846, GHSA-48q6-hpwm-mqh2, ROOT-OS-DEBIAN-11-CVE-2026-45846, ROOT-OS-DEBIAN-12-CVE-2026-45846 and 4 more.