# CVE-2026-23043: btrfs: fix NULL pointer dereference in do_abort_log_replay()

> A local attacker can cause a kernel crash via a NULL pointer dereference in the btrfs filesystem log replay abort path.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 4 Feb 2026
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2026-23043, DEBIAN-CVE-2026-23043, GHSA-79jf-89ph-wp26, UBUNTU-CVE-2026-23043

## What is CVE-2026-23043?

CVE-2026-23043 is a vulnerability in Linux, published on 4 Feb 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:

btrfs: fix NULL pointer dereference in do_abort_log_replay()

Coverity reported a NULL pointer dereference issue (CID 1666756) in
do_abort_log_replay(). When btrfs_alloc_path() fails in
replay_one_buffer(), wc->subvol_path is NULL, but btrfs_abort_log_replay()
calls do_abort_log_replay() which unconditionally dereferences
wc->subvol_path when attempting to print debug information. Fix this by
adding a NULL check before dereferencing wc->subvol_path in
do_abort_log_replay().

## Which versions are affected by CVE-2026-23043?


## How do I fix CVE-2026-23043?

Apply the vendor's patch.

## Is CVE-2026-23043 being exploited?

There is no known exploitation of CVE-2026-23043 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-23043 and fix it if it is affected.

What it is: CVE-2026-23043 is a vulnerability in Linux, published on 4 Feb 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-2026-23043 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-2026-23043/ (Markdown: https://insights.sbomify.com/CVE-2026-23043/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-23043
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-23043
- OSV: https://osv.dev/vulnerability/CVE-2026-23043

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-23043/
Summaries are generated and may contain mistakes; the official description above is the record.