CVE-2026-84191
LibreNMS before 26.5.0 Stored XSS via SNMP VRF fields
Description
LibreNMS before 26.5.0 contains stored cross-site scripting vulnerabilities in VRF display pages where mplsVpnVrfDescription, vrf_name, and mplsVpnVrfRouteDistinguisher fields from SNMP polling are rendered without sanitization. Attackers controlling a monitored network device can inject arbitrary JavaScript through SNMP responses that executes in the browser of any user viewing VRF-related pages.
INFO
Published Date :
Sept. 1, 2026, 12:17 p.m.
Last Modified :
Sept. 1, 2026, 12:17 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-84191
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 4.0 | MEDIUM | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | MEDIUM | [email protected] |
Solution
- Update LibreNMS to version 26.5.0 or later.
- Sanitize user-supplied input before rendering.
- Implement input validation on SNMP responses.
- Review SNMP polling for potential injection vectors.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-84191.
| URL | Resource |
|---|---|
| https://github.com/librenms/librenms/security/advisories/GHSA-g993-wffj-m3gv | |
| https://www.vulncheck.com/advisories/librenms-before-26.5.0-stored-xss-via-snmp-vrf-fields |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-84191 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-2026-84191
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-84191 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-84191 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Sep. 01, 2026
Action Type Old Value New Value Added Description LibreNMS before 26.5.0 contains stored cross-site scripting vulnerabilities in VRF display pages where mplsVpnVrfDescription, vrf_name, and mplsVpnVrfRouteDistinguisher fields from SNMP polling are rendered without sanitization. Attackers controlling a monitored network device can inject arbitrary JavaScript through SNMP responses that executes in the browser of any user viewing VRF-related pages. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N Added CWE CWE-79 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/84xxx/CVE-2026-84191.json">CVE-2026-84191</a> Added Reference https://github.com/librenms/librenms/security/advisories/GHSA-g993-wffj-m3gv Added Reference https://www.vulncheck.com/advisories/librenms-before-26.5.0-stored-xss-via-snmp-vrf-fields