XSS in Librenms
CVE-2026-27016
LibreNMS is an auto-discovering PHP/MySQL/SNMP based network monitoring tool. Versions 24.10.0 through 26.1.1 are vulnerable to Stored XSS via the unit parameter in Custom OID. The Custom OID functionality lacks strip_tags() sanitization while other fields (name, oid, datatype) are sanitized. The unsanitized value is stored in the database and rendered without HTML escaping. This issue is fixed in version 26.2.0.
Vulnerability class: XSS (Cross-Site Scripting)
EPSS: 0.002 (13.6th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.
Affected products
- Librenms — versions >= 24.10.0, < 26.2.0
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Third Party Advisory)
- security-advisories@github.com (x_refsource_MISC, Issue Tracking)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (Product, x_refsource_MISC, Release Notes)
Frequently asked questions
- What is CVE-2026-27016?
- CVE-2026-27016 is a medium-severity vulnerability in Librenms, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2026-02-20.
- How severe is CVE-2026-27016?
- Medium severity. CVSS v3 base score is 5.4 out of 10.