CVE-2026-93045 bpf: Reject arena frees below the arena base
A flaw in the Linux kernel BPF arena allows out-of-bounds memory access, potentially enabling privilege escalation or code execution.
- 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-2026-93045?
CVE-2026-93045 is a high-severity memory corruption 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: Reject arena frees below the arena base
bpf_arena_free_pages() accepts scalar arena addresses. The runtime masks the address to the low 32 bits and reconstructs a full user address from the arena base before returning the range to the arena free tree.
When the scalar value is below the low 32 bits of the arena base, full_uaddr falls below user_vm_start. The existing upper-end clipping then turns this into an out-of-range free-tree offset. A later allocation can reuse that offset and return an address below the arena mapping.
Reject such frees before computing the clipped range.
Which versions are affected by CVE-2026-93045?
How do I fix CVE-2026-93045?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-93045 being exploited?
There is no known exploitation of CVE-2026-93045 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-93045, DEBIAN-CVE-2026-93045, GHSA-qfvw-mjm8-22x7, UBUNTU-CVE-2026-93045.