User enumeration in Nagvis' Checkmk MultisiteAuth before version 1.9.48 allows an unauthenticated attacker to enumerate Checkmk usernames.
Conclusion & alert: CVE-2025-39665 is rated Low Risk (33.5/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.06%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.
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 | 2026-05-02 | 0.04% | 0.06% | +0.01% |
| 2 | 2026-05-01 | 0.05% | 0.04% | -0.01% |
| 3 | 2026-01-04 | — | 0.05% | — |
Full EPSS history (5 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 6.9 | 4.0 | MEDIUM |
|
— | — | [email protected] |
| 5.3 | 3.1 | MEDIUM |
|
3.9 | 1.4 | [email protected] |
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
not yet assigned | CVE-2025-39665 not yet assigned priority: Debian including 1 source packages (nagvis), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): open 3, resolved 2. | https://security-tracker.debian.org/tracker/CVE-2025-39665 |
ubuntu
|
medium | CVE-2025-39665 medium priority: Ubuntu including 1 source packages (nagvis), 7 status rows across 7 suites (bionic, jammy, noble, plucky, questing, upstream, xenial): needs-triage 5, ignored 1, released 1. | https://ubuntu.com/security/CVE-2025-39665 |
| URL | Tags |
|---|---|
| https://github.com/NagVis/nagvis/pull/411/commits/4acabcf9d5b2d26f390e760f59def8e163908d66 | Patch |
| https://www.nagvis.org/downloads/changelog/1.9.48 | Release Notes Vendor Advisory |