n8n: Prototype Pollution via Workflow Credentials Leads to Unauthenticated User and Project Enumeration
HighCVE-2026-59206 · Published Jul 22, 2026
Affected versions
| Package | Affected | Fixed in |
|---|---|---|
| n8n npm | < 1.123.61 | 1.123.61 |
| >= 2.28.0, < 2.28.1 | 2.28.1 | |
| >= 2.0.0-rc.0, < 2.27.4 | 2.27.4 |
Details and references
## Impact An authenticated user with the default `workflow:create` permission could pollute `Object.prototype` through a crafted workflow saved, updated, or imported via the workflow API. This can be leveraged to bypass authentication, allowing unauthenticated requests to be treated as a privileged user and exposing endpoints such as the user and project listings. As a result, every account's personal data (email, role, MFA status) and all projects on the instance may be disclosed to unauthenticated callers. The pollution can also corrupt global state, making parts of the instance unresponsive until restarted. ## Patches The issue has been fixed in n8n versions 1.123.61, 2.27.4, and 2.28.1. Users should upgrade to one of these versions or later to remediate the vulnerability. ## Workarounds If upgrading is not immediately possible, administrators should consider the following temporary mitigations: - Restrict workflow creation and editing permissions to fully trusted users only. - Restrict network access to the n8n instance to trusted users only. These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.
- CVSS 4.0
- CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:L/VA:N/SC:L/SI:L/SA:N
- Severity from
- GitHub (reviewed advisory)
- Weakness
- CWE-1321
- Also known as
- CVE-2026-59206
More n8n advisories
All n8n| Date | Advisory | Severity | Fixed in |
|---|---|---|---|
| Jul 22 | n8n: AI Agents Project Viewer Privilege Escalation via run_node_tool CVE-2026-65015Highfixed in 2.29.8, 2.30.1 | High | 2.29.8, 2.30.1 |
| Jul 22 | n8n: Race Condition in Git Clone Node Allows Authenticated Users to Achieve Remote Code Execution CVE-2026-65598Highfixed in 1.123.64, 2.29.8, 2.30.1 | High | 1.123.64, 2.29.8, 2.30.1 |
| Jul 22 | n8n: DOM-Based XSS via Unsandboxed iframe srcdoc in HTML Preview CVE-2026-65597Highfixed in 1.123.64, 2.29.8, 2.30.1 | High | 1.123.64, 2.29.8, 2.30.1 |
| Jul 22 | n8n: Stored DOM XSS via Resource Locator `cachedResultUrl` CVE-2026-65592Highfixed in 1.123.64, 2.29.8, 2.30.1 | High | 1.123.64, 2.29.8, 2.30.1 |
| Jul 22 | n8n: Google Service Account Private Key Exposed in JWT Header CVE-2026-65599Mediumfixed in 1.123.64, 2.29.8, 2.30.1 | Medium | 1.123.64, 2.29.8, 2.30.1 |
| Jul 22 | n8n: Shared Credential Header Leak via HTTP Request Pagination Expression CVE-2026-59209Highfixed in 1.123.61, 2.27.4, 2.28.1 | High | 1.123.61, 2.27.4, 2.28.1 |