What’s Vulnerable › Vulnerabilities
CVE-2026-90990: Livestatus injection via monitoring filter values
- Severity: medium (CVSS 5.3 v4.0)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.4% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-09-22 · updated 2026-09-22
- Weakness: CWE-93
Description
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.
Affected products
- Checkmk GmbH Checkmk: from 2.5.0 before 2.5.0p14 — fixed in 2.5.0p14
How to fix
Upgrade to a fixed version: Checkmk GmbH Checkmk 2.5.0p14. Check the vendor advisory for mitigations.
References
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