CVE-2026-120495Checkmk GmbH Checkmk
NVD
Vulnerability Summary
Path traversal in the Synthetic Monitoring "Robotmk" test service of Checkmk <2.5.0p19, <2.4.0p40, and 2.3.0 (EOL) allows an attacker who controls the agent output of a monitored host's check output for a host to inject a crafted robot output to define the contents and location for the generated HTML log, leading to code execution as the site user.
CVSS v4.0 Base Metrics — Score 9.4 (CRITICAL)
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:HAttack VectorNetwork
Attack ComplexityLow
Attack RequirementsNone
Privileges RequiredLow
User InteractionNone
Confidentiality (Vulnerable System)High
Integrity (Vulnerable System)High
Availability (Vulnerable System)High
Confidentiality (Subsequent System)High
Integrity (Subsequent System)High
Availability (Subsequent System)High
Affected & Patched Versions
- Checkmk GmbH Checkmk >= 2.5.0 and < 2.5.0p19
- Checkmk GmbH Checkmk >= 2.4.0 and < 2.4.0p40
- Checkmk GmbH Checkmk 2.3.0
- Checkmk GmbH Checkmk 2.5.0p19
- Checkmk GmbH Checkmk 2.4.0p40
What to do
Plan remediation soon. No exploitation is confirmed yet, but the severity is critical.
- Check whether you run Checkmk GmbH Checkmk and which version.
- Update to a patched version listed above, then confirm the new version.
Timeline
- Nov 11, 2026Published
- Nov 14, 2026Record last modified
Score, severity and exploitation changes are tracked from the day Watchtower started logging them.
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Set up CVE alertsExternal References
- Referencehttps://checkmk.com/werk/22624
Data last checked: Nov 14, 2026 05:11 UTC