CVE-2025-38432 net: netpoll: Initialize UDP checksum field before checksumming
A missing UDP checksum initialization in the Linux kernel netpoll module causes IPv6 transmission failures, potentially leading to denial of service.
- 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-2025-38432?
CVE-2025-38432 is a medium-severity denial of service vulnerability in Linux kernel, published on 25 Jul 2025. 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: netpoll: Initialize UDP checksum field before checksumming
commit f1fce08e63fe ("netpoll: Eliminate redundant assignment") removed the initialization of the UDP checksum, which was wrong and broke netpoll IPv6 transmission due to bad checksumming.
udph->check needs to be set before calling csum_ipv6_magic().
Which versions are affected by CVE-2025-38432?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2025-38432?
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-2025-38432 being exploited?
There is no known exploitation of CVE-2025-38432 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2025-38432, GHSA-wj97-6gr4-gfmq, UBUNTU-CVE-2025-38432.