CVE-2026-127236

MEDIUMCVSS 5.4/10

Last modified

CVE-2026-127236 is a medium-severity vulnerability rated 5.4/10 on the CVSS scale. An argument injection vulnerability exists in the ad-hoc RRD graph feature of multiple versions of OpenNMS Meridian and Horizon. The ad-hoc graph endpoint (GET /graph/graph.png?adhoc=true) copies request parameters into the rrdtool command line without validation.

Description

An argument injection vulnerability exists in the ad-hoc RRD graph feature of multiple versions of OpenNMS Meridian and Horizon. The ad-hoc graph endpoint (GET /graph/graph.png?adhoc=true) copies request parameters into the rrdtool command line without validation. A low-privileged authenticated user (ROLE_USER or ROLE_DASHBOARD) can insert extra rrdtool arguments. An injected --daemon argument makes the server connect to an attacker-chosen address, which is a server-side request forgery. An injected DEF statement reads a local RRD file by absolute path. The command runs through exec with an argument array and no shell, so arbitrary operating system command execution is not possible. The fix validates the ad-hoc graph parameters against allowlists. The solution is to upgrade to Meridian 2024.3.15, 2025.0.12, 2026.0.2 and Horizon 36.0.6 or newer. Meridian and Horizon installation instructions state that they are intended for installation within an organization's private networks and should not be directly accessible from the Internet.

Metrics

Weakness Enumeration

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
The OpenNMS GroupMeridian>= 2024.1.0, < 2024.3.15; >= 2025.0.0, < 2025.0.12; >= 2026.0.0, < 2026.0.2
The OpenNMS GroupHorizon>= 36.0.0, < 36.0.6

References

Timeline

Published
Last Modified
Status
Awaiting Analysis

Frequently Asked Questions

What is CVE-2026-127236?
An argument injection vulnerability exists in the ad-hoc RRD graph feature of multiple versions of OpenNMS Meridian and Horizon. The ad-hoc graph endpoint (GET /graph/graph.png?adhoc=true) copies request parameters into the rrdtool command line without validation. A low-privileged authenticated user (ROLE_USER or ROLE_DASHBOARD) can insert extra rrdtool arguments. An injected --daemon argument makes the server connect to an attacker-chosen address, which is a server-side request forgery. An injected DEF statement reads a local RRD file by absolute path. The command runs through exec with an argument array and no shell, so arbitrary operating system command execution is not possible. The fix validates the ad-hoc graph parameters against allowlists. The solution is to upgrade to Meridian 2024.3.15, 2025.0.12, 2026.0.2 and Horizon 36.0.6 or newer. Meridian and Horizon installation instructions state that they are intended for installation within an organization's private networks and should not be directly accessible from the Internet.
How severe is CVE-2026-127236?
CVE-2026-127236 has a CVSS score of 5.4/10 (MEDIUM severity).
How do I fix CVE-2026-127236?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST