CVE-2026-2728 LibreNMS: Cross-Site Scripting in ShowConfigController

What is CVE-2026-2728?

CVE-2026-2728 is a medium-severity cross-site scripting vulnerability in Librenms Librenms, published on 13 Apr 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.

Official description

LibreNMS versions before 26.3.0 are affected by an authenticated Cross-site Scripting vulnerability on the showconfig page. Successful exploitation requires administrative privileges. Exploitation could result in XSS attacks being performed against other users with access to the page.

Weakness: CWE-79

Which versions are affected by CVE-2026-2728?

2 open source packages ship an affected version, including librenms/librenms. It affects 1 product.

Products include Librenms Librenms.

How do I fix CVE-2026-2728?

Upgrade librenms/librenms to 26.3.0 or later.

Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.

Is CVE-2026-2728 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-2728 exists.

Other vulnerabilities in Librenms Librenms

• CVE-2023-4982 Cross-site Scripting (XSS) - Stored in librenms/librenms Critical 9.8
• CVE-2022-29712 Command injection in librenms Critical 9.8
• CVE-2021-44278 Path traversal in librenms/librenms Critical 9.8
• CVE-2019-10665 LibreNMS Information Disclosure Critical 9.8
• CVE-2018-20434 LibreNMS arbitrary OS commands execution Critical 9.8

All Librenms Librenms vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-5gm9-622f-qcg5.