CVE-2025-47711: There's a flaw in the nbdkit server when handling responses from its plugins regarding the status of data bloc

Routine

MEDIUM 6.5WATCHLISTMITIGATEMITIGATEMITIGATE

CVE-2025-47711 is a medium-severity flaw (CVSS 6.5) affecting nbdkit, enterprise linux, enterprise linux advanced virtualization. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

On your watchlist

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	6.5 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.5% (top 60%)
CISA exploited list	No
Weakness	CWE-193
Published	2025-06-09
Last modified	2026-06-30

Publisher (CNA): Red Hat, Inc. · Vendor: nbdkit project · redhat

Last updated 2026-06-30 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2025-06-09 06:15 UTCPublished CVE record published
2026-06-30 05:17 UTCUpdated Record last modified

nbdkit project nbdkit MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy nbdkit || rpm -q nbdkit || nbdkit --version

No fixed or unaffected release known

Apply the vendor mitigation from the advisory, disable the affected feature, or restrict network access.

redhat enterprise linux MITIGATE

Affected: 7.0 · 8.0 · 9.0 · 10.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 7.0

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

redhat enterprise linux advanced virtualization MITIGATE

Affected: 8.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 8.0

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2025-47711?

nbdkit: mitigate or apply the listed mitigation; enterprise linux: mitigate or apply the listed mitigation; enterprise linux advanced virtualization: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2025-47711 being exploited?

CVE-2025-47711 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2025-47711 affect?

CVE-2025-47711 affects nbdkit, enterprise linux, enterprise linux advanced virtualization. Severity is medium (CVSS 6.5). 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

How urgent is CVE-2025-47711?

Priority 38/100. On your watchlist

Related CVEs

CVE-2025-47712 MEDIUM 6.5 MITIGATE A flaw exists in the nbdkit "blocksize" filter that can be triggered by a specific type of client request

References

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