CVE-2026-90159 bpf: Disallow bpf_{g,s}etsockopt() in cgroup UNIX getname hooks
A local attacker with high privileges can trigger a kernel warning and potential instability by calling specific BPF helpers in cgroup UNIX getname hooks.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-90159?
CVE-2026-90159 is a denial of service vulnerability in Linux, published on 17 Sep 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:
bpf: Disallow bpf_{g,s}etsockopt() in cgroup UNIX getname hooks
_bpf_setsockopt() and _bpf_getsockopt() call sock_owned_by_me() for full sockets, so these helpers expect the socket lock to be held.
BPF_CGROUP_UNIX_GETPEERNAME and BPF_CGROUP_UNIX_GETSOCKNAME run BPF programs without acquiring the socket lock. A program attached to either hook can therefore trigger the sock_owned_by_me() warning by calling bpf_setsockopt() or bpf_getsockopt().
Disallow bpf_setsockopt() and bpf_getsockopt() for CGROUP_UNIX_GETPEERNAME and CGROUP_UNIX_GETSOCKNAME.
Which versions are affected by CVE-2026-90159?
How do I fix CVE-2026-90159?
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-2026-90159 being exploited?
There is no known exploitation of CVE-2026-90159 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-90159, DEBIAN-CVE-2026-90159, GHSA-rcrw-xvqq-c49m, UBUNTU-CVE-2026-90159.