Vulnerability in Checkmk Gmbh

CVE-2026-90990

Improper neutralization of newlines in filter values in the monitoring host and service list APIs in Checkmk <2.5.0p14 allows an authenticated user to inject additional Livestatus query headers, bypassing object visibility restrictions in count queries to infer information about hosts and services outside their contact groups and occupying web server and Livestatus workers for an attacker-controlled duration.

Vulnerability class: CRLF Injection

Published · last modified .

EPSS exploit prediction

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Affected products

Weakness classification (CWE)

References