CVE-2026-19135 json
OpenNMS JEXL sandbox bypass in Measurements REST API allows ROLE_USER to load arbitrary classes
published 2026-08-13 2 mo ago modified 2026-09-08 2 mo ago also EUVD-2026-57718
- cvss
- 5.4
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 21%
- public exploits
- 0
- none known
Summary
A 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.
Patch / fix
- The OpenNMS Group Meridian 2024.3.12, 2025.0.9
- The OpenNMS Group Horizon 36.0.3
- github.com/OpenNMS/opennms#8754 pull request
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 2 mo ago
Exploit prediction
0.29% chance of exploitation in the next 30 days, higher than 21% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 5.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N |
Affected products
- The OpenNMS Group Meridian
- The OpenNMS Group Horizon
Classification
- Weakness
-
- CWE-470 Use of Externally-Controlled Input to Select Classes or Code
References
Sources
- CVE List CVE-2026-19135
- NVD CVE-2026-19135
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.