How severe is CVE-2025-39665?

CVE-2025-39665 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2025-39665 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (13th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-39665?

CVE-2025-39665 affects Nagvis. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-39665?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2025-39665 have an EU (EUVD) identifier?

Yes. CVE-2025-39665 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-200737.

When was CVE-2025-39665 published?

CVE-2025-39665 was published on 2025-12-03 and last updated on 2026-06-17.

CVE-2025-39665

CVE-2025-39665 is a medium-severity vulnerability in Nagvis with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-203.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
CVSS v4: 6.9
EPSS exploit prediction: 0% (13th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-200737
Weakness: CWE-203
Affected product: Nagvis
Published: 2025-12-03
Last modified: 2026-06-17

Description

User enumeration in Nagvis' Checkmk MultisiteAuth before version 1.9.48 allows an unauthenticated attacker to enumerate Checkmk usernames.

Frequently asked questions

What is CVE-2025-39665?: User enumeration in Nagvis' Checkmk MultisiteAuth before version 1.9.48 allows an unauthenticated attacker to enumerate Checkmk usernames.
How severe is CVE-2025-39665?: CVE-2025-39665 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2025-39665 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (13th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-39665?: CVE-2025-39665 affects Nagvis. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-39665?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-39665 have an EU (EUVD) identifier?: Yes. CVE-2025-39665 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-200737.
When was CVE-2025-39665 published?: CVE-2025-39665 was published on 2025-12-03 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:nagvis:nagvis:*:*:*:*:*:*:*:*

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