CVE-2026-2859

Unauthenticated Host Enumeration via Observable Response Discrepancy on Deploy Agent Endpoint

CVSS 6.3 MEDIUMEPSS 0.2%CWE-204

Vexday Risk Score

13Low

SSVC decision (CISA)

Track

No exploitation signal → monitor

CVSS 6.3EPSS 0.2%KEV nãoPoC —Nuclei —Metasploit —Patch —

Lifecycle

13 Mar 2026Published on NVD

Recommendation: Monitor — no exploitation signal at the moment.

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.

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

Affected products

Checkmk GmbH · Checkmk

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References

https://checkmk.com/werk/18994