Incorrect authorization in n8n - CVE-2026-33720
Published: April 30, 2026
Vulnerability identifier: #VU128725
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-33720
CWE-ID: CWE-863
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: n8n
Affected software:
n8n
n8n
Detailed vulnerability description
The vulnerability allows a remote attacker to access and use a victim's OAuth tokens.
The vulnerability exists due to incorrect authorization in the OAuth callback handler when processing OAuth callback requests with N8N_SKIP_AUTH_ON_OAUTH_CALLBACK set to true. A remote attacker can trick a victim into completing an OAuth flow against an attacker-controlled credential object to access and use a victim's OAuth tokens.
Only instances with N8N_SKIP_AUTH_ON_OAUTH_CALLBACK=true explicitly configured are vulnerable.
How to mitigate CVE-2026-33720
Install security update from vendor's website.