CVE-2026-98394 af_unix: Return immediately when manage_oob() returns NULL for 0-length buffer.
A local attacker can cause a busy-wait denial of service in the Linux kernel by triggering a specific condition in the af_unix socket implementation.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-98394?
CVE-2026-98394 is a denial of service vulnerability in Linux, published on 14 Oct 2026. 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:
af_unix: Return immediately when manage_oob() returns NULL for 0-length buffer.
Fahad Alharbi reported that recv(0, MSG_PEEK) triggers busy-wait in unix_stream_read_generic() if recv() is blocking and the last skb in the queue is MSG_OOB skb.
In such a situation, TCP returns 0 immediately regardless of blocking or non-blocking.
Let's follow the behaviour.
Which versions are affected by CVE-2026-98394?
How do I fix CVE-2026-98394?
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-2026-98394 being exploited?
There is no known exploitation of CVE-2026-98394 in the wild and no public exploit code.
Sources
Also known as AZL-108119, BELL-CVE-2026-98394, DEBIAN-CVE-2026-98394, GHSA-78rw-466c-3p7p, UBUNTU-CVE-2026-98394.