What’s Vulnerable › Vulnerabilities
CVE-2026-2859: Unauthenticated Host Enumeration via Observable Response Discrepancy on Deploy Agent Endpoint
- Severity: medium (CVSS 4.3 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.2% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-03-13 · updated 2026-06-17
- Weakness: CWE-204
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.
Affected products
- Checkmk GmbH Checkmk: 2.2.0, 2.2.0-b1, 2.2.0-b2, 2.2.0-b3, 2.2.0-b4, 2.2.0-b5 (+129)
References
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