# CVE-2026-23278: netfilter: nf_tables: always walk all pending catchall elements

> A use-after-free in Linux kernel netfilter allows local attackers to cause a system crash via crafted netlink transactions.

- **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:** 20 Mar 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-80207, BELL-CVE-2026-23278, DEBIAN-CVE-2026-23278, GHSA-5vxp-pqjj-287g, ROOT-OS-DEBIAN-11-CVE-2026-23278, ROOT-OS-DEBIAN-12-CVE-2026-23278, ROOT-OS-DEBIAN-13-CVE-2026-23278, ROOT-OS-UBUNTU-2204-CVE-2026-23278, ROOT-OS-UBUNTU-2404-CVE-2026-23278, UBUNTU-CVE-2026-23278

## What is CVE-2026-23278?

CVE-2026-23278 is a high-severity use after free vulnerability in Linux kernel, published on 20 Mar 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: nf_tables: always walk all pending catchall elements

During transaction processing we might have more than one catchall element:
1 live catchall element and 1 pending element that is coming as part of the
new batch.

If the map holding the catchall elements is also going away, its
required to toggle all catchall elements and not just the first viable
candidate.

Otherwise, we get:
 WARNING: ./include/net/netfilter/nf_tables.h:1281 at nft_data_release+0xb7/0xe0 [nf_tables], CPU#2: nft/1404
 RIP: 0010:nft_data_release+0xb7/0xe0 [nf_tables]
 [..]
 __nft_set_elem_destroy+0x106/0x380 [nf_tables]
 nf_tables_abort_release+0x348/0x8d0 [nf_tables]
 nf_tables_abort+0xcf2/0x3ac0 [nf_tables]
 nfnetlink_rcv_batch+0x9c9/0x20e0 [..]

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2026-23278?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-23278?

Apply the vendor's patch.

## Is CVE-2026-23278 being exploited?

There is no known exploitation of CVE-2026-23278 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-23278 and fix it if it is affected.

What it is: CVE-2026-23278 is a high-severity use after free vulnerability in Linux kernel, published on 20 Mar 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-2026-23278 in the wild and no public exploit code.

Affected product: Linux kernel. 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-2026-23278/ (Markdown: https://insights.sbomify.com/CVE-2026-23278/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-23278
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-23278
- OSV: https://osv.dev/vulnerability/CVE-2026-23278

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-23278/
Summaries are generated and may contain mistakes; the official description above is the record.