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.
Published: 2026-09-22
Score: 5.3 Medium
EPSS: n/a
KEV: No
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories

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References
History

Tue, 22 Sep 2026 14:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 22 Sep 2026 10:45:00 +0000

Type Values Removed Values Added
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.
Title Livestatus injection via monitoring filter values
First Time appeared Checkmk
Checkmk checkmk
Weaknesses CWE-93
CPEs cpe:2.3:a:checkmk:checkmk:*:*:*:*:*:*:*:*
Vendors & Products Checkmk
Checkmk checkmk
References
Metrics cvssV4_0

{'score': 5.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: Checkmk

Published:

Updated: 2026-09-22T13:04:48.692Z

Reserved: 2026-09-14T14:17:32.990Z

Link: CVE-2026-90990

cve-icon Vulnrichment

Updated: 2026-09-22T13:04:43.351Z

cve-icon NVD

Status : Deferred

Published: 2026-09-22T11:17:25.960

Modified: 2026-09-22T14:17:17.830

Link: CVE-2026-90990

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-22T11:30:09Z

Weaknesses
  • CWE-93

    Improper Neutralization of CRLF Sequences ('CRLF Injection')