The Opennms Group Horizon vulnerabilities

22 vulnerabilities

Known vulnerabilities in The Opennms Group Horizon, newest first, with CVSS severity, EPSS, KEV listings, ransomware use and the affected versions.

9.1CriticalCVE-2026-111235the opennms group · horizon +1 moreOpenNMS REST authorization bypass via non-canonical HTTP methodAn 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.EPSS0.38%6.5MediumCVE-2026-111252the opennms group · horizon +1 moreOpenNMS denial of service via XML entity expansionA 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.EPSS0.25%6.9MediumCVE-2025-53121the opennms group · horizon +1 moreStored XSS in multiple 33.0.8files in opennms/opennmsMultiple stored XSS were found on different nodes with unsanitized parameters in OpenMNS Horizon 33.0.8 and versions earlier than 33.1.6 on multiple platforms that allow an attacker to store on database and then inject HTML and/or Javascript on the page. The solution is to upgrade to Horizon 33.1.6, 33.1.7 or Meridian 2024.2.6, 2024.2.7 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. OpenNMS thanks Fábio Tomé for reporting this issue.EPSS0.24%6.9MediumCVE-2025-53122the opennms group · horizon +1 moreSQLi in OpenNMS Horizon and MeridianImproper Neutralization of Special Elements used in an SQL Command ('SQL Injection') vulnerability in OpenNMS Horizon and Meridian applications allows SQL Injection.  Users should upgrade to Meridian 2024.2.6 or newer, or Horizon 33.16 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.EPSS0.24%5.9MediumCVE-2026-19596the opennms group · horizon +1 moreOpenNMS XML collector XXE allows arbitrary file read from the OpenNMS hostAn 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.EPSS0.21%5.4MediumCVE-2026-19135ubuntu · horizon +2 moreOpenNMS JEXL sandbox bypass in Measurements REST API allows ROLE_USER to load arbitrary classesA JEXL expression sandbox bypass exists in multiple versions of OpenNMS Meridian and Horizon. A low-privileged authenticated user can submit a crafted expression to the Measurements REST API that escapes the sandbox and loads arbitrary Java classes on the server. This can potentially allow an attacker to gain access to confidential information and compromise integrity. 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.EPSS0.29%4.3MediumCVE-2026-19182the opennms group · horizon +1 moreOpenNMS v2 Alarm REST API inverted authorization check lets ROLE_REST users acknowledge alarms as any user and bypass read-onlyAn 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.EPSS0.25%8.2HighCVE-2026-89054the opennms group · horizonOpenNMS missing authorization on /api/v2 PATCH endpoints allows unauthenticated configuration changesA missing authorization vulnerability in OpenNMS Horizon allows configuration changes without authentication. The Spring Security policy for the /api/v2 REST API defines authorization rules for every HTTP method except PATCH, so the shipped @PATCH configuration endpoints for event configuration and SNMP data collection (which enable and disable event definitions and data-collection sources) are reachable with no authorization enforced. An unauthenticated attacker able to reach the web UI can disable event definitions and SNMP data collection, suppressing event and alarm generation and stopping metric collection - silently degrading monitoring and detection - with the change persisted and reloaded into the running system. The solution is to upgrade to 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.EPSS0.51%6.5MediumCVE-2026-89089the opennms group · horizon +1 moreOpenNMS SQL injection in shipped Asset Management JasperReports via the DATE_FORMAT parameter (ROLE_USER)A SQL injection vulnerability exists in the JasperReports-based reporting feature of multiple versions of OpenNMS Meridian and Horizon. A low-privileged authenticated user (ROLE_USER) can run the shipped, default-enabled online reports "Maintenance contracts expired" (AssetManagementMaintExpired) and "Maintenance contracts strategy" (AssetManagementMaintStrategy) via the reporting REST API (POST /rest/reports/{id}) and supply a DATE_FORMAT parameter that the report templates substitute literally, un-escaped, into their SQL queries. This lets an attacker execute arbitrary SQL against the OpenNMS database and read arbitrary data, including database-stored secrets such as provisioning and notification credentials and SNMP community strings. 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.EPSS0.36%8.8HighCVE-2023-40313Mavenorg.opennms · opennms-base-assembly +4 moreDisable BeanShell Interpreter Remote Server ModeA BeanShell interpreter in remote server mode runs in OpenMNS Horizon versions earlier than 32.0.2 and in related Meridian versions which could allow arbitrary remote Java code execution. The solution is to upgrade to Meridian 2023.1.6, 2022.1.19, 2021.1.30, 2020.1.38 or Horizon 32.0.2 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.EPSS0.78%6.1MediumCVE-2023-40314Mavenorg.opennms · opennms-webapp +3 moreCross-site scripting in bootstrap.jspThe solution is to upgrade to Horizon 32.0.5 or newer and Meridian 2023.1.9 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. OpenNMS thanks Moshe Apelbaum for reporting this issue.EPSS0.43%6.7MediumCVE-2023-40312Mavenorg.opennms · opennms-webapp +4 moreReflected XSS in multiple JSP files in opennms/opennmsMultiple reflected XSS were found on different JSP files with unsanitized parameters in OpenMNS Horizon 31.0.8 and versions earlier than 32.0.2 on multiple platforms that an attacker can modify to craft a malicious XSS payload. The solution is to upgrade to Meridian 2023.1.6, 2022.1.19, 2021.1.30, 2020.1.38 or Horizon 32.0.2 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. OpenNMS thanks Jordi Miralles Comins for reporting this issue.EPSS0.64%6.7MediumCVE-2023-40311Mavenorg.opennms · opennms-webapp +4 moreStored XSS in multiple JSP files in opennms/opennmsMultiple stored XSS were found on different JSP files with unsanitized parameters in OpenMNS Horizon 31.0.8 and versions earlier than 32.0.2 on multiple platforms that allow an attacker to store on database and then load on JSPs or Angular templates. The solution is to upgrade to Meridian 2023.1.6, 2022.1.19, 2021.1.30, 2020.1.38 or Horizon 32.0.2 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. OpenNMS thanks Jordi Miralles Comins for reporting this issue.EPSS0.74%8HighCVE-2023-40612opennms · horizon +3 moreAuthenticated XXE Injection Via The File EditorIn OpenMNS Horizon 31.0.8 and versions earlier than 32.0.2, the file editor which is accessible to any user with ROLE_FILESYSTEM_EDITOR privileges is vulnerable to XXE injection attacks. The solution is to upgrade to Meridian 2023.1.5 or Horizon 32.0.2 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. OpenNMS thanks Erik Wynter for reporting this issue.EPSS0.42%8HighCVE-2023-40315Mavenorg.opennms · opennms-webapp-rest +4 moreROLE_FILESYSTEM_EDITOR Can Be Used To Escalate To ROLE_ADMINIn OpenMNS Horizon 31.0.8 and versions earlier than 32.0.2 and related Meridian versions, any user that has the ROLE_FILESYSTEM_EDITOR can easily escalate their privileges to ROLE_ADMIN or any other role. The solution is to upgrade to Meridian 2023.1.5 or Horizon 32.0.2 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. OpenNMS thanks Erik Wynter for reporting this issue.EPSS2.85%6.7MediumCVE-2023-0846Mavenorg.opennms · opennms +4 moreUnauthenticated, stored XSS in display of alarm reduction-keyUnauthenticated, stored cross-site scripting in the display of alarm reduction keys in multiple versions of OpenNMS Horizon and Meridian could allow an attacker access to confidential session information. Users should upgrade to Meridian 2023.1.0 or newer, or Horizon 31.0.4. 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.EPSS0.49%6.1MediumCVE-2023-0871Mavenorg.opennms.core · org.opennms.core.xml +4 moreAn XML External Entity injection vulnerabilityXXE injection in /rtc/post/ endpoint in OpenMNS Horizon 31.0.8 and versions earlier than 32.0.2 on multiple platforms is vulnerable to XML external entity (XXE) injection, which can be used for instance to force Horizon to make arbitrary HTTP requests to internal and external services. The solution is to upgrade to Meridian 2023.1.6, 2022.1.19, 2021.1.30, 2020.1.38 or Horizon 32.0.2 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. OpenNMS thanks Erik Wynter and Moshe Apelbaum for reporting this issue.EPSS0.55%6.1MediumCVE-2023-0869Mavenorg.opennms · opennms-web-api +4 moreCross-site scripting in outage/list.htmThe solution is to upgrade to Meridian 2023.1.0 or newer, or Horizon 31.0.4 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.EPSS0.41%6.8MediumCVE-2023-0815Mavenorg.opennms · opennms +4 morePlaintext Password Present in the Web logsPotential Insertion of Sensitive Information into Jetty Log Files in multiple versions of OpenNMS Meridian and Horizon could allow disclosure of usernames and passwords if the logging level is set to debug. Users should upgrade to Meridian 2023.1.0 or newer, or Horizon 31.0.4. 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.EPSS0.63%8.2HighCVE-2023-0872Mavenorg.opennms · opennms-webapp-rest +4 moreROLE_REST can be used to escalate to ROLE_ADMIN via /rest/usersThe Horizon REST API includes a users endpoint in OpenMNS Horizon 31.0.8 and versions earlier than 32.0.2 on multiple platforms is vulnerable to elevation of privilege. The solution is to upgrade to Meridian 2023.1.6, 2022.1.19, 2021.1.30, 2020.1.38 or Horizon 32.0.2 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. OpenNMS thanks Erik Wynter for reporting this issue.EPSS3.31%