CVE-2026-74473 vxlan: use pskb_network_may_pull() in route_shortcircuit()
A missing network header pull in the Linux kernel VXLAN driver allows out-of-bounds reads, potentially causing crashes or information leaks.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-74473?
CVE-2026-74473 is a critical memory corruption 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 pskb_network_may_pull() in route_shortcircuit()
route_shortcircuit() currently calls pskb_may_pull(skb, sizeof(struct iphdr)) (or ipv6hdr), which checks if bytes are available starting from skb->data.
However, in vxlan_xmit(), skb->data points to the MAC header, so skb_network_offset(skb) is ETH_HLEN (14 bytes). Using pskb_may_pull(skb, 20) only checks 20 bytes from skb->data (which is 14 bytes MAC header + 6 bytes of IP header), leaving the rest of the IP header potentially un-pulled in non-linear frags. Subsequent dereferences of ip_hdr(skb)->daddr can read beyond the pulled linear buffer length.
Fix this by using pskb_network_may_pull(), which adds skb_network_offset(skb) to the length check to ensure the full network header is present in the linear buffer.
Which versions are affected by CVE-2026-74473?
How do I fix CVE-2026-74473?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-74473 being exploited?
There is no known exploitation of CVE-2026-74473 in the wild and no public exploit code.
Sources
Also known as AZL-96497, BELL-CVE-2026-74473, DEBIAN-CVE-2026-74473, GHSA-h9rh-wf2h-cr4c, UBUNTU-CVE-2026-74473.