CVE-2026-74475 vxlan: use neigh_ha_snapshot() in route_shortcircuit()
A race condition in the Linux kernel VXLAN module allows torn reads of MAC addresses, potentially causing data corruption or denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-74475?
CVE-2026-74475 is a critical vulnerability in Linux, published on 15 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
vxlan: use neigh_ha_snapshot() in route_shortcircuit()
The neighbour hardware address n->ha can be updated asynchronously by the neighbour subsystem, protected by n->ha_lock seqlock. Reading n->ha without holding the seqlock loop can lead to torn reads or reading a partially updated MAC address.
Use neigh_ha_snapshot() in route_shortcircuit() to safely copy n->ha under read_seqbegin()/read_seqretry() lock protection before using it.
Note that arp_reduce() and neigh_reduce() seem to have the same issue left for future patches.
Which versions are affected by CVE-2026-74475?
How do I fix CVE-2026-74475?
Apply the vendor's patch.
Is CVE-2026-74475 being exploited?
There is no known exploitation of CVE-2026-74475 in the wild and no public exploit code.
Sources
Also known as AZL-96015, BELL-CVE-2026-74475, DEBIAN-CVE-2026-74475, GHSA-g8xx-g6f9-m789, UBUNTU-CVE-2026-74475.