Vulnerability-Lookup

GHSA-9HQX-G6F2-RJ2P

Vulnerability from github – Published: 2026-09-10 21:31 – Updated: 2026-09-10 21:31

Details

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.

Severity

5.9 (Medium)


                  
                    CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

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{
  "affected": [],
  "aliases": [
    "CVE-2026-19596"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-611"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-10T21:17:25Z",
    "severity": "MODERATE"
  },
  "details": "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\u0027s 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.\n\n\n\nThe 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\u0027s private networks and should not be directly accessible from the Internet.",
  "id": "GHSA-9hqx-g6f2-rj2p",
  "modified": "2026-09-10T21:31:36Z",
  "published": "2026-09-10T21:31:36Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-19596"
    },
    {
      "type": "WEB",
      "url": "https://github.com/OpenNMS/opennms/pull/8782"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-19596 (GCVE-0-2026-19596)

Vulnerability from cvelistv5 – Published: 2026-09-10 20:08 – Updated: 2026-09-10 20:27

Title

OpenNMS XML collector XXE allows arbitrary file read from the OpenNMS host

Summary

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.

Severity

5.9 (Medium)


                        
                          CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-10 20:27 UTC

CWE

CWE-611 - Improper Restriction of XML External Entity Reference

Assigner

OpenNMS mitre root

References

1 reference

URL	Tags
https://github.com/OpenNMS/opennms/pull/8782	patch

Impacted products

2 products

Vendor	Product	Version
The OpenNMS Group	Meridian	Affected: 2024.1.0 , < 2024.3.13 (maven) Affected: 2025.0.0 , < 2025.0.10 (maven)
The OpenNMS Group	Horizon	Affected: 36.0.0 , < 36.0.4 (maven)

Credits

Keith Lee, Foregenix

Show details on NVD website

JSON

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                "id": "CVE-2026-19596",
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                  },
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                    "Technical Impact": "partial"
                  }
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                "role": "CISA Coordinator",
                "timestamp": "2026-09-10T20:27:39.274555Z",
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Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.

Action not permitted

GHSA-9HQX-G6F2-RJ2P

CVE-2026-19596 (GCVE-0-2026-19596)

Tags

Sightings

Nomenclature