Prototype Pollution in N8n
CVE-2026-59206
n8n is an open source workflow automation platform. Prior to 1.123.61, 2.27.4, and, 2.28.1, 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, allowing unauthenticated requests to be treated as a privileged user and exposing user and project listing endpoints. This issue is fixed in versions 1.123.61, 2.27.4, and 2.28.1.
Vulnerability class: Prototype Pollution
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:L.
EPSS exploit prediction
EPSS: 0.007 (50.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 50th percentile — 50.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: 0.000
Affected products
- N8n — versions 2.28.0
- N8n-Io N8n — versions >= 2.28.0, < 2.28.1, >= 2.0.0-rc.0, < 2.27.4, < 1.123.61
Weakness classification (CWE)
References
- github.com/n8n-io/n8n/security/advisories/GHSA-75qm-gp28-rcq9 (Vendor Advisory)
- github.com/n8n-io/n8n/releases/tag/n8n@2.27.4 (Release Notes)
- github.com/n8n-io/n8n/releases/tag/n8n@2.28.1 (Release Notes)
Frequently asked questions
- What is CVE-2026-59206?
- CVE-2026-59206 is a high-severity vulnerability in N8n, classified under Improperly Controlled Modification of Object Prototype Attributes (Prototype Pollution). CVSS score: 7.1/10. Published 2026-07-09.
- How severe is CVE-2026-59206?
- High severity. CVSS v3 base score is 7.1 out of 10.