This page tracks the Ubuntu fix status. The vulnerability itself is described on the main CVE page. View CVE-2026-15576 →

UBUNTU-CVE-2026-15576

Improper authentication in the agent receiver of Checkmk

Original description

The description as published by the source.

Improper authentication in the agent receiver of Checkmk <2.5.0p10 allows an unauthenticated remote attacker to bypass mutual TLS client certificate verification of relay endpoints by supplying a fixed placeholder identity in the request URL, resulting in limited impact on integrity and availability. Only the Cloud, Ultimate and Ultimate MT editions are affected, as other editions do not expose relay endpoints.

Source: OSV.dev (Open Source Vulnerabilities) OSV

Affected packages

Ubuntu:Pro:16.04:LTS check-mk

[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]

Ubuntu:18.04:LTS check-mk

[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]

References

report ubuntu.com
report cve.org