CVE-2026-99057 xen/netfront: don't leak the skb when xennet_fill_frags() fails
- Exploited in the wild
- Not known
- Fix
- Available
What is CVE-2026-99057?
CVE-2026-99057 is a vulnerability in Linux, published on 23 Oct 2026.
Official description
In the Linux kernel, the following vulnerability has been resolved:
xen/netfront: don't leak the skb when xennet_fill_frags() fails
When a response chain has more slots than fit in the skb's frags, xennet_fill_frags() returns an error and xennet_poll() jumps to its error path. That path moves what's left on tmpq to errq to be freed, but the skb being filled was already dequeued from tmpq, so it's never freed. Each chain that overflows leaks the skb and the pages attached to it as frags, and the backend decides how many slots it sends.
Put the skb back on tmpq before taking the error path, like the xennet_set_skb_gso() failure just above it does.
Which versions are affected by CVE-2026-99057?
How do I fix CVE-2026-99057?
Upgrade to a fixed version.
Is CVE-2026-99057 being exploited?
There is no known exploitation of CVE-2026-99057 in the wild and no public exploit code.
Sources
Also known as AZL-110942, BELL-CVE-2026-99057, DEBIAN-CVE-2026-99057, GHSA-32c4-hc77-g5cm, UBUNTU-CVE-2026-99057.