CVE-2026-19596OpenNMS XML collector XXE allows arbitrary file read from the OpenNMS host
Updated under an hour ago ()
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It affects The OpenNMS Group Meridian and 1 other product. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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Free account, 1 product
An XML External Entity (XXE) vulnerability exists in the XML collector of multiple versions of OpenNMS Meridian and Horizon. When OpenNMS collects XML from a source whose response is attacker-controlled (for example a compromised monitored host or an HTTP man-in-the-middle position), the collector's XML parser resolves external entities and external DTDs. This allows an attacker to read files accessible to the OpenNMS service account, including database credentials, and to induce out-of-band requests. The solution is to upgrade to Meridian 2024.3.13, 2025.0.10 and Horizon 36.0.4 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
- 5.9 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
- Weakness (CWE)
- CWE-611
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- OpenNMS
- NVD analysis
- Awaiting Analysis
- Record last updated
- Sep 10, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
The OpenNMS Group Meridian opennms_group:meridian (from the name) | from 2024.1.0 before 2024.3.13; from 2025.0.0 before 2025.0.10 | CNA record |
The OpenNMS Group Horizon opennms_group:horizon (from the name) | from 36.0.0 before 36.0.4 | CNA record |
References
- https://github.com/OpenNMS/opennms/pull/8782patch
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.