# CVE-2025-47712: Nbd: nbdkit: integer overflow triggers an assertion resulting in denial of service

> An integer overflow in the nbdkit blocksize filter allows a client to trigger an assertion failure, causing a denial of service.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 9 Jun 2025
- **Updated:** 30 Jun 2026
- **Also known as:** AZL-63798, AZL-63875, CLSA-2026-1777021155, DEBIAN-CVE-2025-47712, GHSA-fpfc-3gjg-hfhp, UBUNTU-CVE-2025-47712

## What is CVE-2025-47712?

CVE-2025-47712 is a medium-severity vulnerability in Red Hat Enterprise Linux 10, published on 9 Jun 2025. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A flaw exists in the nbdkit "blocksize" filter that can be triggered by a specific type of client request. When a client requests block status information for a very large data range, exceeding a certain limit, it causes an internal error in the nbdkit, leading to a denial of service.

Weakness: CWE-190 (Integer Overflow or Wraparound)

## Which versions are affected by CVE-2025-47712?

It affects 1 product.


Products: Nbdkit Project Nbdkit.

## How do I fix CVE-2025-47712?

Apply the vendor's patch.

## Is CVE-2025-47712 being exploited?

There is no known exploitation of CVE-2025-47712 in the wild and no public exploit code.

## Other vulnerabilities in Red Hat Enterprise Linux 10

- [CVE-2025-47711](https://insights.sbomify.com/CVE-2025-47711/): Nbdkit: nbdkit-server: off-by-one error when processing block status may lead to a denial of service (medium 6.5)
- [CVE-2019-14851](https://insights.sbomify.com/CVE-2019-14851/): Denial of service in nbdkit (medium 6.5)
- [CVE-2019-14850](https://insights.sbomify.com/CVE-2019-14850/): Denial of service in nbdkit (low 3.7)
- [CVE-2021-3716](https://insights.sbomify.com/CVE-2021-3716/): Other in nbdkit (low 3.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-47712 and fix it if it is affected.

What it is: CVE-2025-47712 is a medium-severity vulnerability in Red Hat Enterprise Linux 10, published on 9 Jun 2025. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-47712 in the wild and no public exploit code.

Affected product: Red Hat Enterprise Linux 10. 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-2025-47712/ (Markdown: https://insights.sbomify.com/CVE-2025-47712/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-47712
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-47712
- OSV: https://osv.dev/vulnerability/CVE-2025-47712

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-47712/
Summaries are generated and may contain mistakes; the official description above is the record.