by Kastro
Paper/Archive/CVE-2026-120495

CVE-2026-120495

Checkmk GmbH Checkmk — Arbitrary file write and code execution via crafted Synthetic Monitoring agent data

CVSS 9.4
critical.is priorityof 100
28
CVSS 9.4 (CNA)9.4 / 10 × 3028.2Not in CISA KEV+300.0No EPSS score.000 × 200.0No public exploit+100.0SSVC exploitation: unknown+100.0
Description · from the CVE record

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.

Affected

ProductAffectedFixed inSource
Checkmk2.5.0 – < 2.5.0p192.5.0p19CNA
Checkmk2.4.0 – < 2.4.0p402.4.0p40CNA
Checkmk2.3.0–CNA

Scores by source

Checkmk (CNA)9.4CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

References

advisorycheckmk.com/werk/22624