Cross-Site Scripting (XSS) in n8n (CVE-2026-103249)
Summary
Cross-site scripting in n8n (CVE-2026-103249). Confidential information can be exposed externally.
Original description
The description as published by the source.
n8n versions before 1.123.80, from 2.0.0 before 2.39.6, and from 2.40.0 before 2.40.1 contain a stored DOM cross-site scripting vulnerability in Resource Locator parameter dropdown link handling. Workflow authors can inject malicious script URLs that execute arbitrary JavaScript in the editor origin when other users open the node dropdown and click the external-link icon, with the payload persisting across workflow imports and shares.
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-103249 has been found in n8n.
Confidential information can be exposed externally. CVSS score: 7.6/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "n8n CVE-2026-103249" on the vendor's site.
CVE-2026-103249 (n8n) — CWE-79 / CVSS v3 7.6
Attack vector: remote (network-reachable)
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.
Cross-site scripting (XSS) (CWE-79) exists in n8n.
Check the vendor advisory for the affected versions of n8n.
Severity: High (CVSS 7.6/10). Confidential information can be exposed externally.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'n8n' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'n8n' . | 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
n8nを grep し、稼働しているサービス・バージョンを把握する。 -
2Post-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。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
References
- web github.com
- web vulncheck.com
- web nvd.nist.gov
- web github.com