CVE-2026-19182: medium-severity vulnerability in The OpenNMS Group Meridian
OpenNMS v2 Alarm REST API inverted authorization check lets ROLE_REST users acknowledge alarms as any user and bypass read-only
Published
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13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 4.3epss 0.3%
An incorrect authorization check in the v2 Alarm REST API in OpenNMS Meridian and Horizon allows a low-privileged authenticated user (ROLE_REST) to acknowledge, escalate, or clear alarms recorded as an arbitrary username, and, when also assigned ROLE_READONLY, to modify alarm state despite the read-only restriction. A credential check that should restrict these operations is guarded by an inverted condition, so it never executes for a real (non-blank) username. This can potentially allow an attacker to compromise the integrity of alarm state and audit records.
The solution is to upgrade to Meridian 2024.3.12, 2025.0.9 and Horizon 36.0.3 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.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
Related CVEs — The OpenNMS Group Meridian
In the same product, most dangerous first.
CVE-2023-0872HIGHROLE_REST can be used to escalate to ROLE_ADMIN via /rest/usersEPSS 3.3%CVE-2023-40315MEDIUMROLE_FILESYSTEM_EDITOR Can Be Used To Escalate To ROLE_ADMINEPSS 2.9%CVE-2023-40313HIGHDisable BeanShell Interpreter Remote Server ModeEPSS 0.8%CVE-2023-40311MEDIUMStored XSS in multiple JSP files in opennms/opennmsEPSS 0.7%CVE-2023-40312MEDIUMReflected XSS in multiple JSP files in opennms/opennmsEPSS 0.6%CVE-2023-0815MEDIUMPlaintext Password Present in the Web logsEPSS 0.6%