CVE-2026-2859

Unauthenticated Host Enumeration via Observable Response Discrepancy on Deploy Agent Endpoint

State: Published
Severity: 6.3 Medium
Published: Mar 13, 2026
Updated: Mar 13, 2026
Reserved: Feb 20, 2026

Description

Improper permission enforcement in Checkmk versions 2.4.0 before 2.4.0p23, 2.3.0 before 2.3.0p43, and 2.2.0 (EOL) allows unauthenticated users to enumerate existing hosts by observing different HTTP response codes in deploy_agent endpoint, which could lead to information disclosure.

Scores

CVSS	Score	Vector	Source
4.0	6.3 Medium	CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N	Checkmk

Weaknesses

CWE-204 Observable Response Discrepancy

Affected Products

Product	Versions
CheckmkCheckmk GmbH	2.4.0 to before 2.4.0p23Affected 2.3.0 to before 2.3.0p43Affected 2.2.0Affected

References

https://checkmk.com/werk/18994

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