CVE-2026-56359: n8n - Cross-Site Scripting in Credential Management OAuth2 Authorization URL

Severity: medium (CVSS 5.4 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-07-08 · updated 2026-10-29
Weakness: CWE-79

Description

n8n before 2.8.0 contains a cross-site scripting vulnerability in the credential management flow where authenticated users can inject malicious JavaScript URLs into OAuth2 credential Authorization URL fields. Attackers can craft malicious credentials and trick victims into clicking the OAuth authorization button, executing arbitrary scripts in their browser session with the victim's privileges.

Affected products

n8n-io n8n: before 2.6.4; from 2.7.0 before 2.8.0 — fixed in 2.6.4, 2.8.0
n8n-io n8n: from 2.7.0 before 2.8.0 — fixed in 2.8.0

How to fix

Upgrade to a fixed version: n8n-io n8n 2.6.4, 2.8.0; n8n-io n8n 2.8.0. Check the vendor advisory for mitigations.

References

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