# CVE-2026-106547: HDF5 heap buffer overflow in H5VM_array_fill via crafted fill-value metadata

> A heap buffer overflow in HDF5 allows remote attackers to execute arbitrary code or crash applications via crafted file metadata.

- **Severity:** High 8.5 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **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:** 6 Oct 2026
- **Updated:** 7 Oct 2026
- **Also known as:** AZL-106679, DEBIAN-CVE-2026-106547, ECHO-f72a-4ae2-b841, GHSA-p24g-8x6r-2v93, UBUNTU-CVE-2026-106547

## What is CVE-2026-106547?

CVE-2026-106547 is a high-severity memory corruption vulnerability in The HDF Group HDF5, published on 6 Oct 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

A heap-based buffer overflow in H5VM_array_fill() in src/H5VM.c in HDF5 before 2.2.0 lets a remote attacker cause an application crash and possibly execute arbitrary code with a crafted HDF5 file. When a dataset's unallocated chunks are read, H5D__fill_init() fills the fill-value buffer from datatype and dataspace metadata in the file. If that metadata is inconsistent with the buffer's allocated size, the write goes past the end of the buffer. The attacker can control the content written through the fill value stored in the file.

Weakness: CWE-122 (Heap-based Buffer Overflow)

## Which versions are affected by CVE-2026-106547?


## How do I fix CVE-2026-106547?

Upgrade to a fixed version.

## Is CVE-2026-106547 being exploited?

There is no known exploitation of CVE-2026-106547 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-106547 and fix it if it is affected.

What it is: CVE-2026-106547 is a high-severity memory corruption vulnerability in The HDF Group HDF5, published on 6 Oct 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-2026-106547 in the wild and no public exploit code.

Affected product: The HDF Group 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-2026-106547/ (Markdown: https://insights.sbomify.com/CVE-2026-106547/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-106547
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-106547
- OSV: https://osv.dev/vulnerability/CVE-2026-106547

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-106547/
Summaries are generated and may contain mistakes; the official description above is the record.