CVE-2026-2859

Summary

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 Software

VendorProductVersion RangeStatus
Checkmk GmbHCheckmk2.4.0 < 2.4.0p23affected
Checkmk GmbHCheckmk2.3.0 < 2.3.0p43affected
Checkmk GmbHCheckmk2.2.0affected

Weaknesses

  • CWE-204: CWE-204: Observable Response Discrepancy

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: yes
    • Technical Impact: partial

References