CVE-2026-98417 net: xfrm: reject unrepresentable espintcp transport headers
A remote attacker can cause a denial of service in the Linux kernel by sending crafted ESP-in-TCP packets that trigger a transport header offset warning.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-98417?
CVE-2026-98417 is a denial of service vulnerability in Linux, published on 14 Oct 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:
net: xfrm: reject unrepresentable espintcp transport headers
ESP-in-TCP can hand xfrm packets whose transport header offset no longer fits after the stream parser trims the TCP envelope. The plain transport header reset truncates that offset and triggers the skb warning path.
Use the careful transport-header helper and drop the skb through the existing XFRM error path when the offset cannot be represented.
Which versions are affected by CVE-2026-98417?
How do I fix CVE-2026-98417?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-98417 being exploited?
There is no known exploitation of CVE-2026-98417 in the wild and no public exploit code.
Sources
Also known as AZL-108126, BELL-CVE-2026-98417, DEBIAN-CVE-2026-98417, GHSA-mmvw-8jc6-xq5j, UBUNTU-CVE-2026-98417.