CVE-2025-47711

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

MEDIUM
6.5
CVSS Score
Published: June 9, 2025 at 06:03 AM UTC
Updated: June 30, 2026 at 05:17 AM UTC
3 products affected across 2 vendorsEnterprise LinuxEnterprise Linux Advanced VirtualizationNbdkit

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Severity
MEDIUM6.5
Exploit prediction
EPSS 0.5%
SSVC
No known exploit

Description

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Vendor states this is fixed in 7 (unknown)
Vendor states this is fixed in 8 (unknown)
Vendor states this is fixed in 8 (unknown)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

6.5MEDIUMredhat
Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-193

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