A flaw exists in the nbdkit "blocksize" filter that can be triggered by a specific type of client request. When a client requests block status information for a very large data range, exceeding a certain limit, it causes an internal error in the nbdkit, leading to a denial of service.
Conclusion & alert: CVE-2025-47712 is rated Moderate Risk (43.9/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 0.27%). Mandatory action: Review affected assets and schedule remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-04-05 | 0.05% | 0.27% | +0.22% |
| 2 | 2025-08-16 | 0.04% | 0.05% | +0.02% |
| 3 | 2025-06-09 | — | 0.04% | — |
Full EPSS history (3 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 6.5 | 3.1 | MEDIUM |
|
2.8 | 3.6 | [email protected] |
| 6.5 | 3.1 | MEDIUM |
|
2.8 | 3.6 | [email protected] |
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
not yet assigned | CVE-2025-47712 not yet assigned priority: Debian including 1 source packages (nbdkit), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 3, open 2. | https://security-tracker.debian.org/tracker/CVE-2025-47712 |
redhat
|
medium | — | https://access.redhat.com/security/cve/CVE-2025-47712 |
suse
|
medium | CVE-2025-47712 severity moderate: SUSE including 56 source package names (nbd, nbdkit-1.36.5-150400.3.9.1, …), 67 product×package rows across 7 product lines (SUSE Linux Enterprise Module for Package Hub 15 SP6, SUSE Linux Enterprise Module for Package Hub 15 SP7, … (7 product lines)): Fixed 64, Known Not Affected 3. | https://www.suse.com/security/cve/CVE-2025-47712/ |
ubuntu
|
medium | CVE-2025-47712 medium priority: Ubuntu including 1 source packages (nbdkit), 8 status rows across 8 suites (focal, jammy, noble, oracular, plucky, questing, upstream, xenial): needs-triage 6, ignored 2. | https://ubuntu.com/security/CVE-2025-47712 |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| nbdkit_project | nbdkit | — | cpe:2.3:a:nbdkit_project:nbdkit:-:*:*:*:*:*:*:* |
| URL | Tags |
|---|---|
| https://access.redhat.com/security/cve/CVE-2025-47712 | Third Party Advisory |
| https://bugzilla.redhat.com/show_bug.cgi?id=2365724 | Issue Tracking Third Party Advisory |
| https://lists.libguestfs.org/archives/list/[email protected]/thread/67E7AASHHADIY7VAD3FFW2I67LTWVWYF/ | Third Party Advisory |