Medium severity · published Feb 20, 2026
CVE-2026-26989
LibreNMS has Stored XSS in Alert Rule
4.8
CVSS
0.3%
EPSS
No
On KEV
Description
LibreNMS is an auto-discovering PHP/MySQL/SNMP based network monitoring tool. Versions 25.12.0 and below are affected by a Stored Cross-Site Scripting (XSS) vulnerability in the Alert Rules workflow. An attacker with administrative privileges can inject malicious scripts that execute in the browser context of any user who accesses the Alert Rules page. This issue has been fixed in version 26.2.0.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
High
User interaction
Required
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 20% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LI
librenms · librenms
< 26.2.0 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-26989
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-26989
Patch
https://github.com/librenms/librenms/commit/087608cf9f851189847cb8e8e5ad002e59170c58
Issue Tracking
https://github.com/librenms/librenms/pull/19039
Product
https://github.com/librenms/librenms/releases/tag/26.2.0
Exploit
https://github.com/librenms/librenms/security/advisories/GHSA-6xmx-xr9p-58p7
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