# CVE-2026-17574: NULL Pointer Dereference in HDF5 via Invalid Variable-Length Datatype Type Tag

> An attacker can cause a denial of service by tricking a user into opening a crafted HDF5 file with an invalid variable-length datatype.

- **Severity:** Medium 5.2 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 27 Jul 2026
- **Updated:** 27 Jul 2026
- **Also known as:** AZL-94019, DEBIAN-CVE-2026-17574, ECHO-8c91-0553-6384, GHSA-cv7r-692h-j9fh, JLSEC-2026-1386, UBUNTU-CVE-2026-17574

## What is CVE-2026-17574?

CVE-2026-17574 is a medium-severity vulnerability in Hdfgroup Hdf5, published on 27 Jul 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

HDF5 contains a NULL pointer dereference vulnerability. Processing a crafted HDF5 file containing an attribute with an invalid variable-length datatype type field may cause the application to crash when the attribute is read.

Weakness: CWE-617 (Reachable Assertion), CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2026-17574?

It affects 1 product.


Products: Hdfgroup Hdf5.

## How do I fix CVE-2026-17574?

Apply the vendor's patch.

## Is CVE-2026-17574 being exploited?

There is no known exploitation of CVE-2026-17574 in the wild and no public exploit code.

## Other vulnerabilities in Hdfgroup Hdf5

- [CVE-2024-32608](https://insights.sbomify.com/CVE-2024-32608/): Memory corruption in n/a (critical 9.8)
- [CVE-2024-29157](https://insights.sbomify.com/CVE-2024-29157/): Memory corruption in n/a (critical 9.8)
- [CVE-2024-29159](https://insights.sbomify.com/CVE-2024-29159/): Memory corruption in n/a (critical 9.8)
- [CVE-2024-29164](https://insights.sbomify.com/CVE-2024-29164/): Memory corruption in n/a (critical 9.8)
- [CVE-2024-32611](https://insights.sbomify.com/CVE-2024-32611/): Other in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-17574 and fix it if it is affected.

What it is: CVE-2026-17574 is a medium-severity vulnerability in Hdfgroup Hdf5, published on 27 Jul 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-17574 in the wild and no public exploit code.

Affected product: Hdfgroup Hdf5. 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-2026-17574/ (Markdown: https://insights.sbomify.com/CVE-2026-17574/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-17574
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-17574
- OSV: https://osv.dev/vulnerability/CVE-2026-17574

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-17574/
Summaries are generated and may contain mistakes; the official description above is the record.