CVE-2026-2859: Observable Response Discrepancy

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 deployagent endpoint, which could lead to information disclosure...