CVE-2026-65597: n8n before 1.123.64 DOM-Based XSS via Unsandboxed iframe

Severity: medium (CVSS 5.4 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-07-22 · updated 2026-10-29
Weakness: CWE-79

Description

n8n before 1.123.64, 2.x before 2.29.8, and before 2.30.1 contains a DOM-based cross-site scripting vulnerability in the HTML preview, which renders execution output into an iframe srcdoc without the sandbox attribute. A sanitizer bypass allows injected script to execute same-origin as the editor. When a victim opens the preview, the script can call authenticated APIs using the victim's session. An account with global:member privileges can exploit the issue.

Affected products

n8n-io n8n: before 1.123.64; from 2.0.0 before 2.29.8; 2.30.0 (and their updates) — fixed in 1.123.64, 2.29.8
n8n-io n8n: before 1.123.64 — fixed in 1.123.64

How to fix

Upgrade to a fixed version: n8n-io n8n 1.123.64, 2.29.8; n8n-io n8n 1.123.64. Check the vendor advisory for mitigations.

References

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