---
id: CVE-2025-47712
title: >-
  A flaw exists in the nbdkit "blocksize" filter that can be triggered by a
  specific type of client request
summary: >-
  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 erro…
severity: medium
cvss: 6.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-190
vendor: nbdkit_project
product: nbdkit
affected:
  - nbdkit
published: '2025-06-09'
updated: '2026-06-25'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-47712'
references:
  - url: 'https://access.redhat.com/security/cve/CVE-2025-47712'
    label: secalert@redhat.com
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2365724'
    label: secalert@redhat.com
  - url: >-
      https://lists.libguestfs.org/archives/list/guestfs@lists.libguestfs.org/thread/67E7AASHHADIY7VAD3FFW2I67LTWVWYF/
    label: secalert@redhat.com
tags:
  - nvd
epss: 0.00479
epssPercentile: 0.40494
ingestedAt: '2026-06-29T13:24:34.353Z'
---

## Overview

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.

## Affected

- `nbdkit`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.