# CVE-2026-95897: Dask Loader core.py from_npy_stack deserialization

> Remote attackers can achieve code execution via unsafe deserialization in Dask's from_npy_stack function, requiring immediate attention from users of the library.

- **Severity:** Medium 5.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 23 Sep 2026
- **Updated:** 23 Sep 2026
- **Also known as:** DEBIAN-CVE-2026-95897, GHSA-7jm5-7xjw-qq97, UBUNTU-CVE-2026-95897

## What is CVE-2026-95897?

CVE-2026-95897 is a medium-severity unsafe deserialization vulnerability in Dask, published on 23 Sep 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

A security vulnerability has been detected in Dask up to 2026.8.0. This affects the function from_npy_stack of the file dask/array/core.py of the component Loader. Such manipulation leads to deserialization. The attack can be launched remotely. The exploit has been disclosed publicly and may be used. The project was informed of the problem early through an issue report but has not responded yet.

Weakness: CWE-502 (Deserialization of Untrusted Data), CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2026-95897?


## How do I fix CVE-2026-95897?

No fix has been published for CVE-2026-95897 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-95897 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-95897 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-95897 and fix it if it is affected.

What it is: CVE-2026-95897 is a medium-severity unsafe deserialization vulnerability in Dask, published on 23 Sep 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-95897 exists.

Affected product: Dask. 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-2026-95897/ (Markdown: https://insights.sbomify.com/CVE-2026-95897/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-95897
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-95897
- OSV: https://osv.dev/vulnerability/CVE-2026-95897

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-95897/
Summaries are generated and may contain mistakes; the official description above is the record.