CVE Watchtower

CVE-2026-121374Checkmk GmbH Checkmk

NVD

Vulnerability Summary

Argument injection in the Kubernetes special agent in Checkmk <2.5.0p19, <2.4.0p40, and 2.3.0 (EOL) allows a user with permission to edit rules in at least one folder to write files to arbitrary locations writable by the site user via crafted node roles in the "Exclude nodes based on their role" rule option, leading to code execution as the site user.
Severity Level
CRITICAL(9.4)
Published Date
Nov 11, 2026
Last Modified
Nov 14, 2026
Exploitation Status
No confirmed exploitation yet
EPSS Score (30-Day)
0.38%Probability
Root Weakness (CWE)
See the MITRE CWE entry for the full definition of this weakness.
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:H
Attack 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

Affected 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
Patched Versions
  • 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.

  1. Check whether you run Checkmk GmbH Checkmk and which version.
  2. 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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External References

Data last checked: Nov 14, 2026 05:11 UTC