# 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.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **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:** Yes
- **Published:** 15 Aug 2026
- **Updated:** 16 Oct 2026
- **Also known as:** BELL-CVE-2026-72252, DEBIAN-CVE-2026-72252, GHSA-wp7x-h4hq-8jpw, UBUNTU-CVE-2026-72252

## 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.

## Is CVE-2026-72252 being exploited?

There is no known exploitation of CVE-2026-72252 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-72252 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2026-72252 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-72252/ (Markdown: https://insights.sbomify.com/CVE-2026-72252/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-72252
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-72252
- OSV: https://osv.dev/vulnerability/CVE-2026-72252

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-72252/
Summaries are generated and may contain mistakes; the official description above is the record.