CVE-2026-93044 bpf: Disallow interpreter fallback for arena-related insns
A local attacker can trigger a kernel crash by loading BPF programs with arena instructions that force an unsupported interpreter fallback.
- 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-2026-93044?
CVE-2026-93044 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 interpreter fallback for arena-related insns
Since the interpreter does not support the arena-related insns, interpreter fallback should not be allowed for these insns in core.c::__bpf_prog_select_runtime().
Currently, when the interpreter executes the arena ST/LDX/STX insns, it would hit the BUG_ON() in ___bpf_prog_run() at run time.
[ 2.579196] BPF interpreter: unknown opcode a2 (imm: 0x0) [ 2.579998] ------------[ cut here ]------------ [ 2.580652] kernel BUG at kernel/bpf/core.c:2349! [ 2.581314] Oops: invalid opcode: 0000 [#1] SMP PTI
Set jit_required as true when arena map is used in the prog to disallow interpreter fallback for arena-related insns.
Which versions are affected by CVE-2026-93044?
How do I fix CVE-2026-93044?
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-2026-93044 being exploited?
There is no known exploitation of CVE-2026-93044 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-93044, DEBIAN-CVE-2026-93044, GHSA-pp7w-23pg-4fgh, UBUNTU-CVE-2026-93044.