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CVE-2026-111252

OpenNMS denial of service via XML entity expansion

CVSS score

6.5

EPSS probability

—

Risk score

0.7

Published

13 h ago

Official patch verified

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Impact on My Inventory

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Vulnerability description

CVE AI research

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DayBreach AI Explanation

Verified against sources

Denial of Service Vulnerability in OpenNMS Meridian and Horizon

Sources read

1

Source agreement

Tam uyum

Evidence confidence

%55

Short explanation

A denial of service vulnerability exists in the XML parsing mechanism of OpenNMS Meridian and Horizon, exhausting server memory [S0]. Authenticated users with provisioning access can trigger this condition [S0].

Why does it matter?

Authorized attackers can cause memory exhaustion and lead to service disruptions [S0].

What should be done?

  • Upgrade to Meridian 2024.3.14, 2025.0.11, 2026.0.1, or Horizon 36.0.5 [S0].
  • Ensure installations are kept within private networks [S0].
Chain of evidence and sources2 verified claims

OpenNMS Meridian ve Horizon XML ayrıştırma sürecinde varlık genişletme sınırı eksiktir [S0].

Kimliği doğrulanmış ve provizyon erişimi olan kullanıcılar zafiyeti istismar edebilir [S0].

Show the technical text from the sources

A denial of service vulnerability exists in the XML parsing of multiple versions of OpenNMS Meridian and Horizon. OpenNMS parsed XML without an effective limit on entity expansion. A document with a DOCTYPE that declares internal entities can expand to a very large value and exhaust the server memory. An authenticated user with provisioning access can supply such a document through a requisition or foreign-source import, which includes a remote requisition URL that the server fetches and parses. Both deeply nested entities and a single large entity referenced many times cause the memory exhaustion. The fix caps the number of entity expansions for all XML parsing and rejects any DOCTYPE in requisition and foreign-source XML. 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.

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

CWE: CWE-776, CWE-400

Explanation produced with the local gemini-flash-lite-latest model. Numerical metrics and the KEV, patch and exploit statuses are not determined by AI.

IMPACT: Affected Products and Software

Affected Products

The following products are affected by CVE-2026-111252 vulnerability. Where our threat engine knows the exact affected versions, they are listed below.

IDVENDORPRODUCTACTION
1The OpenNMS GroupMeridian View
2The OpenNMS GroupHorizon View
Total affected vendors: 1|Products: 2

RED HAT CSAF/VEX: Product Impact Check

Red Hat has not yet published a CSAF/VEX impact record for this CVE. This does not mean “not affected”.

SCORING: CVSS from Multiple Sources

CVSS Scores

The Common Vulnerability Scoring System is a standardised framework for assessing the severity of vulnerabilities in software and systems. We collect and display CVSS scores from several sources for each CVE.

SCOREVERSIONSEVERITYVECTORSOURCE
6.5CVSS V31MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HNVD
6.5CVSS V3_1MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HCVE CNA

Patch and Remediation Guide

Solution & Remediation Advisory

Patch verified

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cvelist

CNA çözüm referansı

Open source
cvelist

CNA çözüm referansı

Open source
reference

Yama veya çözüm referansı

Open source
reference

Yama veya çözüm referansı

Open source
Confirm the affected product and version against the source evidence above.
Restrict access to internet-facing services and apply network segmentation.
Apply the official update named in the evidence only to the matching product and version.
Monitor server logs and network endpoints for signs of anomalous execution.

Public exploit and active exploitation status

Verified exploit intelligence

No verified public PoC, exploit repository or Metasploit module has been found for this CVE yet.

Weakness Classification and Attack Patterns (CWE & CAPEC)

CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorises the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-111252 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-111252 weaknesses.

Attack Vector and Accessibility

ExposureAğ üzerinden
PermissionsLow
UserGerekmiyor

Official Sources and Advisories

CVSS Vector Radar Chart

6.5 / 10
Attack VectorNetworkComplexityLowPrivilegesLowUser Interact.NoneConfidentialityLowIntegrityNoneAvailabilityHigh

Vulnerability Scoring Details

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredLow privileges
User InteractionNone required
Confidentiality (Gizlilik)Low
Integrity (Bütünlük)None
Availability (Erişilebilirlik)High

Yama doğrulandı

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Weakness Type (CWE & CAPEC)

Similar Vulnerabilities

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