CVE-2025-47712Public exploitNetwork attack vector

Service crash via block-status length overflow

Published Jun 9, 2025 · Updated Jun 30, 2026

Integer overflow in the blocksize filter in Red Hat nbdkit allows remote authenticated users to crash the server through an NBD request. The filter rounds an unaligned block-status length near 4 GiB upward in a 32-bit variable, which wraps to zero and trips an assertion. Exploitation requires access to an export using the blocksize filter and causes only a temporary service interruption, without reported data disclosure or modification.

CVSS severity6.5
Medium
EPSS probability0.48%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Integer overflow in the blocksize filter in Red Hat nbdkit allows remote authenticated users to crash the server through an NBD request. The filter rounds an unaligned block-status length near 4 GiB upward in a 32-bit variable, which wraps to zero and trips an assertion. Exploitation requires access to an export using the blocksize filter and causes only a temporary service interruption, without reported data disclosure or modification.

The record

CVE
CVE-2025-47712
Published
Jun 9, 2025
Updated
Jun 30, 2026
Vendor
389 Directory Server
Product
nbdkit
Classifications
CWE-190, T1499.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 9, 2025CVE publishedPublication date reported by the CVE source.
  2. Jun 30, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1.21.16 <1.38.6
  2. Affected versionversion=1.40.0 <1.40.6
  3. Affected versionversion=1.42.0 <1.42.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

389 Directory Server · nbdkitversion=1.21.16 <1.38.6; version=1.40.0 <1.40.6; version=1.42.0 <1.42.3
389 Directory Server · Red Hat Enterprise Linux 10Affected versions are unavailable in this record.
389 Directory Server · Red Hat Enterprise Linux 9Affected versions are unavailable in this record.

Published CVSS scores

5.3SUSECVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
6.5NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
6.5Red HatCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
6.5SUSECVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
6.5CVE.orgCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-190Integer Overflow or Wraparound
T1499.004Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo