CVE-2025-39665
Unknown Unknown - Not Provided
BaseFortify

Publication date: 2025-12-03

Last updated on: 2025-12-04

Assigner: Checkmk GmbH

Description
User enumeration in Nagvis' Checkmk MultisiteAuth before version 1.9.48 allows an unauthenticated attacker to enumerate Checkmk usernames.
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Meta Information
Published
2025-12-03
Last Modified
2025-12-04
Generated
2026-06-16
AI Q&A
2025-12-03
EPSS Evaluated
2026-06-15
NVD
CVE-2025-39665
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
nagvis nagvis *
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Exploitability
CWE
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KEV
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CWE ID Description
CWE-203 The product behaves differently or sends different responses under different circumstances in a way that is observable to an unauthorized actor, which exposes security-relevant information about the state of the product, such as whether a particular operation was successful or not.
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Impact Analysis

The vulnerability can impact you by allowing attackers to gather valid usernames without authentication, which can be used as a first step in targeted attacks such as brute force or phishing, potentially leading to unauthorized access.

Executive Summary

This vulnerability is a user enumeration issue in Nagvis' Checkmk MultisiteAuth before version 1.9.48. It allows an unauthenticated attacker to discover valid Checkmk usernames by exploiting the authentication mechanism.

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