Admin-to-user script execution via alert-rule rendering
Published Feb 20, 2026 · Updated Feb 20, 2026
Stored XSS in LibreNMS 25.12.0 and earlier allows remote authenticated users with admin access to run JavaScript via crafted alert rules. The Alert Rules list escapes attacker-controlled rule-display data without removing embedded tags before the Bootgrid table interprets it as HTML. Administrative access is required to store the payload, and another user's visit to the Alert Rules page executes it in that user's browser context.
Summary
What happened
Stored XSS in LibreNMS 25.12.0 and earlier allows remote authenticated users with admin access to run JavaScript via crafted alert rules. The Alert Rules list escapes attacker-controlled rule-display data without removing embedded tags before the Bootgrid table interprets it as HTML. Administrative access is required to store the payload, and another user's visit to the Alert Rules page executes it in that user's browser context.
The record
- CVE
- CVE-2026-26989
- Published
- Feb 20, 2026
- Updated
- Feb 20, 2026
- Vendor
- LibreNMS
- Product
- LibreNMS
- Classifications
- CWE-79, T1059.007
- Attack vector
- network
- Privileges
- admin
Timeline
How it unfolded
- Feb 20, 2026CVE publishedPublication date reported by the CVE source.
- Feb 20, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 26.2.0
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- GHSA-6xmx-xr9p-58p7 request PoCproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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