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.
CVE-2026-27016
MEDIUMPre-NVD 5.45.4
EchelonGraph scoreLOW confidence
This medium-severity CVE scores 5.4 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: secondary
5.4EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.4Exploit: None knownExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 5.4
- EG Score
- 5.4(low)
- EG Risk
- 29(Track)EG Risk 29/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity54% × 45%Exploitation0% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 14%
- KEV
- Not listed
Published
February 20, 2026
Last Modified
June 17, 2026
References (4)
- security-advisories@githubhttps://github.com/librenms/librenms/commit/3bea263e02441690c01dea7fa3fe6ffec94af335
- security-advisories@githubhttps://github.com/librenms/librenms/pull/19040
- security-advisories@githubhttps://github.com/librenms/librenms/releases/tag/26.2.0
- security-advisories@githubhttps://github.com/librenms/librenms/security/advisories/GHSA-fqx6-693c-f55g
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 1× in last 7d / 1× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-27 14:13 UTCEG score recompute
Related CVEs(same CWE)
Frequently asked(5)
What is CVE-2026-27016?
CVE-2026-27016 is a medium vulnerability published on February 20, 2026. 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…
When was CVE-2026-27016 disclosed?
CVE-2026-27016 was first published in the National Vulnerability Database on February 20, 2026, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-27016 actively exploited?
CVE-2026-27016 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 86.4% of all scored CVEs.
What is the CVSS score of CVE-2026-27016?
CVE-2026-27016 has a CVSS v3 base score of 5.4 (NVD). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-27016?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-27016, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-27016
Is Your Infrastructure Affected by CVE-2026-27016?
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