Vulnerability-Lookup

GHSA-F5W5-G5CW-7W6G

Vulnerability from github – Published: 2026-10-15 21:36 – Updated: 2026-10-15 21:36

Details

An authorization bypass vulnerability exists in the REST API of multiple versions of OpenNMS Meridian and Horizon. The /rest/** Spring Security filter chains authorize requests with intercept-url rules that name the HTTP method as an uppercase token, compare the method case-sensitively, and have no terminal deny rule. A request that uses a non-canonical (for example lowercase) method token matches no rule and is processed without authentication. A remote, unauthenticated attacker can read the monitored inventory and can create, modify, or delete resources through the REST API, which includes injecting events to fabricate or suppress alarms. The /rest/alarms chain has the same missing deny rule and discloses whether an alarm exists through a difference in the response. The fix adds a terminal deny rule to each REST filter chain.

The solution is to upgrade to Meridian 2024.3.14, 2025.0.11, 2026.0.1 and Horizon 36.0.5 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

9.1 (Critical)


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

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  "affected": [],
  "aliases": [
    "CVE-2026-111235"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-204"
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    "github_reviewed_at": null,
    "nvd_published_at": "2026-10-15T19:17:36Z",
    "severity": "CRITICAL"
  },
  "details": "An authorization bypass vulnerability exists in the REST API of multiple versions of OpenNMS Meridian and Horizon. The /rest/** Spring Security filter chains authorize requests with intercept-url rules that name the HTTP method as an uppercase token, compare the method case-sensitively, and have no terminal deny rule. A request that uses a non-canonical (for example lowercase) method token matches no rule and is processed without authentication. A remote, unauthenticated attacker can read the monitored inventory and can create, modify, or delete resources through the REST API, which includes injecting events to fabricate or suppress alarms. The /rest/alarms chain has the same missing deny rule and discloses whether an alarm exists through a difference in the response. The fix adds a terminal deny rule to each REST filter chain.\n\n\n\nThe solution is to upgrade to Meridian 2024.3.14, 2025.0.11, 2026.0.1 and Horizon 36.0.5 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-f5w5-g5cw-7w6g",
  "modified": "2026-10-15T21:36:12Z",
  "published": "2026-10-15T21:36:12Z",
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    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-111235"
    },
    {
      "type": "WEB",
      "url": "https://github.com/OpenNMS/opennms/pull/8934"
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    }
  ]
}

CVE-2026-111235 (GCVE-0-2026-111235)

Vulnerability from cvelistv5 – Published: 2026-10-15 18:45 – Updated: 2026-10-16 19:59

Title

OpenNMS REST authorization bypass via non-canonical HTTP method

Summary

Severity

9.1 (Critical)


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

SSVC

Exploitation: none Automatable: yes Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-10-16 19:59 UTC

CWE

CWE-862 - Missing Authorization
CWE-863 - Incorrect Authorization
CWE-204 - Observable Response Discrepancy

Assigner

OpenNMS CNA under the mitre root

CNA scorecard – unranked: 7 records in the last 180 days, 10 needed details

References

1 reference

URL	Tags
https://github.com/OpenNMS/opennms/pull/8934	patch

Impacted products

2 products

Vendor	Product	Version
The OpenNMS Group	Meridian	Affected: 2024.1.0 , < 2024.3.14 (maven) Affected: 2025.0.0 , < 2025.0.11 (maven) Affected: 2026.0.0 , < 2026.0.1 (maven)
The OpenNMS Group	Horizon	Affected: 36.0.0 , < 36.0.5 (maven)

Credits

Pongsathon Sirithanyakul, Warunyou Sunpachit, Khamolwan Hnunainam (IT Select Lab Co., Ltd., Thailand)

Show details on NVD website

JSON

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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.

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