---
id: CVE-2023-5871
title: 'Libnbd: malicious nbd server may crash libnbd'
summary: >-
  A flaw was found in libnbd, due to a malicious Network Block Device (NBD), a
  protocol for accessing Block Devices such as hard disks over a Network. This
  issue may allow a malicious NBD server to cause a Denial of Service.
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'
cvssSource: cna
cwe:
  - CWE-617
vendor: Red Hat
product: libnbd
affected:
  - libnbd (all versions)
  - libnbd
  - libnbd
  - 'virt:rhel/libnbd'
published: '2023-11-27'
updated: '2026-11-05'
sourceUpdated: '2026-11-05T11:36:23.350Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2023-5871'
references:
  - url: 'https://access.redhat.com/errata/RHSA-2024:2204'
    label: 'RHSA-2024:2204'
  - url: 'https://access.redhat.com/security/cve/CVE-2023-5871'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2247308'
    label: RHBZ#2247308
  - url: >-
      https://lists.libguestfs.org/archives/list/guestfs@lists.libguestfs.org/thread/PFVUCMPFQUDC23JXSCUUPXIGDZ7XCFMD/
tags:
  - cve.org
epss: 0.01108
epssPercentile: 0.65976
ingestedAt: '2026-11-05T21:36:00.803Z'
---

## Overview

A flaw was found in libnbd, due to a malicious Network Block Device (NBD), a protocol for accessing Block Devices such as hard disks over a Network. This issue may allow a malicious NBD server to cause a Denial of Service.

## Affected

- `libnbd (all versions)`
- `libnbd`
- `libnbd`
- `virt:rhel/libnbd`

## Remediation

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

### Workarounds

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.