CVE-2026-98561 nfp: hold IPsec RX state under the XArray lock
A race condition in the Linux kernel NFP driver allows use-after-free during IPsec RX processing, potentially leading to system crashes or code execution.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-98561?
CVE-2026-98561 is an use after free vulnerability in Linux, published on 18 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:
nfp: hold IPsec RX state under the XArray lock
nfp_net_ipsec_rx() drops the XArray lock before taking a reference to the xfrm_state it found. The delete path can erase the entry and drop the last state reference in that interval. RX can then try to increment a zero refcount after the state has been queued for destruction.
The driver queues firmware invalidation asynchronously; the delete path does not wait for the command to complete or drain pending RX processing.
The XFRM garbage collector waits for an RCU grace period before freeing the state. That delays reclamation but does not make acquiring a reference from zero valid.
Take the xfrm_state reference before releasing the XArray lock so xa_erase() cannot run between lookup and reference acquisition.
Which versions are affected by CVE-2026-98561?
How do I fix CVE-2026-98561?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-98561 being exploited?
There is no known exploitation of CVE-2026-98561 in the wild and no public exploit code.
Sources
Also known as AZL-108786, BELL-CVE-2026-98561, DEBIAN-CVE-2026-98561, GHSA-6wr4-6g5h-j9qm, UBUNTU-CVE-2026-98561.