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.
CVE-2025-47711
CVSS base score
6.5 (v3.1)
Severity
MEDIUM
Attack vector
Network
Weakness
CWE-193
Last modified
November 5, 2026
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Affected products
nbdkit project nbdkit
redhat enterprise linux
redhat enterprise linux advanced virtualization
References
- access.redhat.com Vendor Advisory
- bugzilla.redhat.com Issue Tracking
- lists.libguestfs.org