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CVE-2026-2728
Cross-Site Scripting (XSS) in librenms/librenms (CVE-2026-2728)
Summary
cross-site scripting in librenms/librenms (CVE-2026-2728). Risk of unauthorized operations or information disclosure. Exploitable via ``rancid_repo_url``. Mitigation: upgrade to `26.3.0` or later.
AI summary snake-internal / snake-material-v2
A vulnerability tracked as **CVE-2026-2728** has been found in librenms/librenms.
Attackers can target a specific entry point like ``rancid_repo_url`` over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: ?/10.
What to do: upgrade librenms/librenms to **26.3.0** or later.
If unsure, ask your IT team or search "librenms/librenms CVE-2026-2728" on the vendor's site.
CVE-2026-2728 (librenms/librenms) — CWE-79 /
Attack vector: remote (network-reachable)
Attack surface: `rancid_repo_url` / `href` / `rancid_configs` / `Config`
Patched: `26.3.0` — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
❓ What is the problem
**Cross-site scripting (XSS)** (CWE-79) exists in librenms/librenms. Attackers reach the vulnerable code path via ``rancid_repo_url`` without authentication.
📍 Affected scope
librenms/librenms — . Attack surface: `rancid_repo_url` / `href` / `rancid_configs` / `Config`.
🔥 Severity
Severity: ?. Risk of unauthorized operations or information disclosure
🔧 How to fix
Update to **26.3.0**.
🛡️ Workaround
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
🔍 Detection
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run `grep -r 'librenms/librenms' .` against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response Actions (7 steps)
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'librenms/librenms' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で `librenms/librenms` を grep し、稼働しているサービス・バージョンを把握する。
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6Apply patch patch
Upgrade librenms/librenms to 26.3.0ステージング環境で 26.3.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスと、Step 3 で見つけた異常検知の続報チェックを含めること。
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7Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番では Step 3 と同じログクエリでアラート再発が無いか継続監視。
Affected packages
composer
librenms/librenms
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"26.3.0"}]}]
Packagist
librenms/librenms
[{"type":"ECOSYSTEM","events":[{"introduced":"25.12.0"},{"fixed":"26.3.0"}]}]
References
- advisory https://nvd.nist.gov/vuln/detail/CVE-2026-2728
- package https://github.com/librenms/librenms
- web https://projectblack.io/blog/librenms-authenticated-rce-and-xss/#xss-on-showconfig-page-2630
- web https://github.com/advisories/GHSA-rp7w-624x-95qv
- web https://github.com/librenms/librenms/security/advisories/GHSA-5gm9-622f-qcg5
- web https://github.com/librenms/librenms/releases/tag/26.3.0
- web https://github.com/advisories/GHSA-5gm9-622f-qcg5