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Fencer Vulns
medium 6.5

CVE-2025-47711 json

Nbdkit: nbdkit-server: off-by-one error when processing block status may lead to a denial of service

published 2025-06-09 17 mo ago modified 2026-11-05 3 d ago also EUVD-2025-17431

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 42%
public exploits
0
none known

Summary

There's a flaw in the nbdkit server when handling responses from its plugins regarding the status of data blocks. If a client makes a specific request for a very large data range, and a plugin responds with an even larger single block, the nbdkit server can encounter a critical internal error, leading to a denial-of-service.

Patch / fix

  • nbdkit Debian 14, Debian 13 1.42.3-1

debian advisories DEBIAN-CVE-2025-47711

  • nbdkit SLE Module for Server Applications 15 SP6, openSUSE Leap 15.6 1.36.5-150400.3.9.1
  • nbdkit SLE Module for Server Applications 15 SP7 1.40.6-150700.4.3.1

suse advisories SUSE-SU-2025:01889-1SUSE-SU-2025:01888-1

  • nbdkit openSUSE Tumbleweed 1.42.3-1.1

opensuse advisories openSUSE-SU-2025:15088-1

  • nbdkit Azure Linux 3.0 1.35.3-7
  • nbdkit CBL-Mariner 2.0 1.35.3-4

azure linux advisories AZL-63801AZL-63878

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-47711 updated cvss 6.5

nbdkit: nbdkit-server: off-by-one error when processing block status may lead to a Denial of Service

  • Red Hat Enterprise Linux 7 nbdkit, nbdkit-plugin-vddk, nbdkit-basic-plugins, nbdkit-plugin-python2, nbdkit-example-plugins, nbdkit-plugin-python-common Red Hat Enterprise Linux 8 nbdkit, nbdkit-server, nbdkit-plugin-xz, nbdkit-xz-filter, nbdkit-nbd-plugin, nbdkit-ssh-plugin, +17 more Red Hat Enterprise Linux 8 Advanced Virtualization nbdkit, nbdkit-server, nbdkit-plugin-xz, nbdkit-xz-filter, nbdkit-nbd-plugin, nbdkit-ssh-plugin, +17 more
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 9 nbdkit, nbdkit-server, nbdkit-selinux, nbdkit-xz-filter, nbdkit-nbd-plugin, nbdkit-ssh-plugin, +12 more Red Hat Enterprise Linux 10 nbdkit
    affected: no fix available “Fix deferred”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
17 mo ago

Exploit prediction

0.48% chance of exploitation in the next 30 days, higher than 42% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Red Hat Red Hat Enterprise Linux 10
  • Red Hat Red Hat Enterprise Linux 7
  • Red Hat Red Hat Enterprise Linux 8
  • Red Hat Red Hat Enterprise Linux 8 Advanced Virtualization
  • Red Hat Red Hat Enterprise Linux 9

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.