# CVE-2026-97605: erofs: preserve LZMA decoders on resize failure

> A null pointer dereference in the Linux kernel's EROFS LZMA decoder allows local attackers to cause a denial of service via mount operations.

- **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:** 25 Sep 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-104309, BELL-CVE-2026-97605, DEBIAN-CVE-2026-97605, GHSA-8cg5-7hqp-6rcp, UBUNTU-CVE-2026-97605

## What is CVE-2026-97605?

CVE-2026-97605 is a vulnerability in Linux, published on 25 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:

erofs: preserve LZMA decoders on resize failure

The pool-resize path frees each stream's old decoder before allocating
its replacement. If an allocation fails after some streams have already
been replaced, the failed stream is put back on the list with state ==
NULL. z_erofs_lzma_max_dictsize is still advanced as if the whole
pool had been resized.

An existing LZMA mount can select the broken stream and pass
NULL to xz_dec_microlzma_reset(). A retry at the same size also
skip another resize attempt. Since the global maximum was advanced,
thus, the invalid state is left unrepaired.

Allocate each replacement before freeing the old decoder, temporarily
retaining one old decoder during allocation. Stop at the first failure
and advance z_erofs_lzma_max_dictsize only after all streams satisfy
the request.

Record each stream's dictionary capacity so retries can skip streams
already enlarged before a partial failure.

## Which versions are affected by CVE-2026-97605?


## How do I fix CVE-2026-97605?

Apply the vendor's patch.

## Is CVE-2026-97605 being exploited?

There is no known exploitation of CVE-2026-97605 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-97605 and fix it if it is affected.

What it is: CVE-2026-97605 is a vulnerability in Linux, published on 25 Sep 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-2026-97605 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-2026-97605/ (Markdown: https://insights.sbomify.com/CVE-2026-97605/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-97605
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-97605
- OSV: https://osv.dev/vulnerability/CVE-2026-97605

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-97605/
Summaries are generated and may contain mistakes; the official description above is the record.