CVE-2026-2728Public exploitNetwork attack vector

Admin-to-admin XSS via unescaped RANCID URL

Published Apr 13, 2026 · Updated Apr 13, 2026

Stored XSS in LibreNMS before 26.3.0 allows remote authenticated users with admin rights to execute scripts in another administrator's browser. The showconfig template places the unvalidated rancid_repo_url value directly into an HTML link attribute without contextual encoding. A valid RANCID Git repository and a second administrator visiting showconfig are required; injected code runs in that administrator's session.

CVSS severity3.5
Low
EPSS probability0.22%
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 26.3.0 allows remote authenticated users with admin rights to execute scripts in another administrator's browser. The showconfig template places the unvalidated rancid_repo_url value directly into an HTML link attribute without contextual encoding. A valid RANCID Git repository and a second administrator visiting showconfig are required; injected code runs in that administrator's session.

The record

CVE
CVE-2026-2728
Published
Apr 13, 2026
Updated
Apr 13, 2026
Vendor
LibreNMS
Product
LibreNMS
Classifications
CWE-79, T1203
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Apr 13, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 13, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <26.3.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

LibreNMS · LibreNMSversion=0 <26.3.0

Published CVSS scores

4.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
3.5GitHubCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:L/A:N
4.6PRJBLKCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:A/VC:N/VI:L/VA:N/SC:N/SI:L/SA: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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 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

See the directory against your own environment.

Your stack

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