What is CVE-2026-3103?

CVE-2026-3103 is a medium-severity vulnerability in Checkmk, classified under Incorrect Authorization. CVSS score: 5.4/10. Published 2026-03-04.

How severe is CVE-2026-3103?

Medium severity. CVSS v3 base score is 5.4 out of 10.

Auth bypass in Checkmk

CVE-2026-3103

A logic error in the remove_password() function in Checkmk GmbH's Checkmk versions <2.4.0p23, <2.3.0p43, and 2.2.0 (EOL) allows a low-privileged user to cause data loss.

Vulnerability class: Broken Access Control

EPSS: 0.002 (7.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L.

Affected products

Checkmk — versions 2.2.0, 2.3.0, 2.4.0
Checkmk Gmbh — versions 2.4.0, 2.3.0, 2.2.0

Weakness classification (CWE)

CWE-863 — Incorrect Authorization

References

security@checkmk.com (Mitigation, Vendor Advisory)

Frequently asked questions

What is CVE-2026-3103?: CVE-2026-3103 is a medium-severity vulnerability in Checkmk, classified under Incorrect Authorization. CVSS score: 5.4/10. Published 2026-03-04.
How severe is CVE-2026-3103?: Medium severity. CVSS v3 base score is 5.4 out of 10.