CVE-2026-19182
What it is
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.
At a glance
- Exploitability
- Can be exploited over the network with a low-privilege account. Limited direct impact.
- Exploit odds
- 0.3% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.3% in the next 30 days (EPSS).
- Severity: 4.3 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.3% · EPSS, next 30 days
- Weakness
- CWE-863 · Incorrect authorization
- Record status
- Awaiting Analysis
Attack profile CVSS 3.1 · 4.3
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- Low
- Availability
- None
Raw vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-19182.md and follow it. Check whether this project is affected by CVE-2026-19182. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
