Auth bypass in N8n
CVE-2026-59208
n8n is an open source workflow automation platform. Prior to 2.27.4 and from 2.28.0 prior to 2.28.1, n8n instances configured with more than one trusted token-exchange issuer resolved external identities to local accounts using only the JWT sub claim and ignored the iss claim, allowing an attacker with a valid token from one trusted issuer and a sub matching a victim under another issuer to authenticate as that victim. This issue is fixed in versions 2.27.4 and 2.28.1.
Vulnerability class: Broken Authentication
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N.
EPSS exploit prediction
EPSS: 0.003 (16.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 17th percentile — 16.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.031 · newest: 0.003 · change: -0.029
Affected products
- N8n — versions 2.28.0
- N8n-Io N8n — versions >= 2.28.0, < 2.28.1, < 2.27.4
Weakness classification (CWE)
References
- github.com/n8n-io/n8n/security/advisories/GHSA-mq3m-f8x3-579w (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-2026-59208?
- CVE-2026-59208 is a medium-severity vulnerability in N8n, classified under Improper Authentication. CVSS score: 6.8/10. Published 2026-07-09.
- How severe is CVE-2026-59208?
- Medium severity. CVSS v3 base score is 6.8 out of 10.