CVE-2026-72252 netfilter: nft_set_pipapo: don't leak bad clone into future transaction
A memory corruption vulnerability in the Linux kernel netfilter subsystem allows out-of-bounds writes, potentially leading to code execution or privilege escalation.
- 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-2026-72252?
CVE-2026-72252 is a high-severity memory corruption vulnerability in Linux, published on 15 Aug 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:
netfilter: nft_set_pipapo: don't leak bad clone into future transaction
On memory allocation failure the cloned nft_pipapo_match can enter a bad state: - some fields can have their lookup tables resized while others did not - bits might have been toggled - scratch map can be undersized which also means m->bsize_max can be lower than what is required
This means that the next insertion in the same batch can trigger out-of-bounds writes.
Furthermore, a failure in the first can result in the bad clone to leak into the next transaction because the abort callback is never executed in this case (the upper layer saw an error and no attempt to allocate a transactional request was made).
Record a state for the nft_pipapo_match structure: - NEW (pristine clone) - MOD (modified clone with good state) - ERR (potentially bogus content)
Then make it so that deletes and insertions fail when the clone entered ERR state.
In case the very first insert attempt results in an error, free the clone right away.
Which versions are affected by CVE-2026-72252?
How do I fix CVE-2026-72252?
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-2026-72252 being exploited?
There is no known exploitation of CVE-2026-72252 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-72252, DEBIAN-CVE-2026-72252, GHSA-wp7x-h4hq-8jpw, UBUNTU-CVE-2026-72252.