CVE-2026-86427
Received Received - Intake

Argument Injection in LibreNMS Graph Title Parameter

Publication date: 2026-09-07

Last updated on: 2026-09-07

Assigner: VulnCheck

Description
LibreNMS before 26.8.0 contains an argument injection vulnerability in the graph_title parameter that allows authenticated attackers to inject arbitrary rrdtool arguments by breaking out of double-quote escaping. Attackers can inject DEF and LINE arguments to read RRD files from unauthorized devices, or use newline injection to execute arbitrary rrdtool commands, bypassing per-device authorization checks.

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Meta Information

Published
2026-09-07
Last Modified
2026-09-07
Generated
2026-09-07
AI Q&A
2026-09-07
EPSS Evaluated
N/A
NVD
CVE-2026-86427
EUVD
EUVD-2026-72385

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
librenms librenms to 26.8.0 (exc)

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-77 The product constructs all or part of a command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended command when it is sent to a downstream component.

Attack-Flow Graph

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Executive Summary

CVE-2026-86427 is an argument injection vulnerability in LibreNMS versions before 26.8.0. It occurs in the graph_title parameter, allowing authenticated attackers to inject arbitrary rrdtool arguments by escaping double quotes. Attackers can inject DEF and LINE arguments to read unauthorized RRD files or execute arbitrary rrdtool commands via newline injection, bypassing per-device authorization checks.

Detection Guidance

To detect this vulnerability, check the LibreNMS version running on your system. If it is before version 26.8.0, it is vulnerable. You can verify the version by running commands like 'cd /opt/librenms && ./validate.php' or checking the web interface under the 'About' section.

Impact Analysis

This vulnerability allows attackers to read sensitive data from unauthorized devices by accessing RRD files. They can also execute arbitrary rrdtool commands, potentially leading to information disclosure or data integrity issues. Exploitation requires authentication, but may be possible without it if allow_unauth_graphs is enabled.

Compliance Impact

This vulnerability could lead to unauthorized access to sensitive data, violating GDPR and HIPAA requirements for data protection and access controls. Organizations using affected LibreNMS versions may face compliance violations due to potential data breaches and unauthorized information disclosure.

Mitigation Strategies

Immediately upgrade LibreNMS to version 26.8.0 or later to patch the vulnerability. If upgrading is not immediately possible, review and restrict access to the graph_title parameter in the application code, particularly in GraphController.php, GraphParameters.php, Graph.php, and Rrd.php.

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