CVE-2026-120495 json
Arbitrary file write and code execution via crafted Synthetic Monitoring agent data
published 23h ago modified 23h ago also EUVD-2026-123351
- cvss
- 9.4
- version 4.0, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- —
- no EPSS score yet
- public exploits
- 0
- none known
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.
Patch / fix
- Checkmk GmbH Checkmk 2.4.0p40, 2.5.0p19
Is CVE-2026-120495 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerCVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 9.4 | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H |
| CNA | 4.0 | 9.4 | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
Affected products
- Checkmk GmbH Checkmk
Classification
- Weakness
-
- CWE-23 Relative Path Traversal
References
-
checkmk.com
/werk/22624
vendor-advisory
Sources
- CVE List CVE-2026-120495
- NVD CVE-2026-120495
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