CVE-2025-55296Public exploitNetwork attack vector

Stored XSS via unescaped alert template names

Published Aug 18, 2025 · Updated Aug 18, 2025

Stored XSS in LibreNMS before 25.8.0 allows remote authenticated users with admin access to execute JavaScript in administrators' browsers. The alert-template list in includes/html/print-alert-templates.php inserts each stored template name into a table cell without HTML escaping. Admin-level access is required to create the template; rendering the list then exposes administrator sessions and page-accessible data.

CVSS severity5.5
Medium
EPSS probability12.46%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in LibreNMS before 25.8.0 allows remote authenticated users with admin access to execute JavaScript in administrators' browsers. The alert-template list in includes/html/print-alert-templates.php inserts each stored template name into a table cell without HTML escaping. Admin-level access is required to create the template; rendering the list then exposes administrator sessions and page-accessible data.

The record

CVE
CVE-2025-55296
Published
Aug 18, 2025
Updated
Aug 18, 2025
Vendor
LibreNMS
Product
LibreNMS
Classifications
CWE-79, T1203
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Aug 18, 2025CVE publishedPublication date reported by the CVE source.
  2. Aug 18, 2025Record 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.

  1. Affected versionversion=< 25.8.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

LibreNMS · LibreNMSversion=< 25.8.0

Published CVSS scores

5.5GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:L/A:N
5.4NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1203Exploitation for Client Execution

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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