n8n before 1.123.25 (1.x) and before 2.11.2 (2.x), with the fix also included in 2.12.0, contains a stored cross-site scripting vulnerability in the Form Trigger node's CSS sanitization that allows authenticated users to inject malicious scripts. Attackers with workflow creation permissions can inject XSS payloads that execute persistently for all form visitors, enabling form hijacking and phishing attacks.
CVE-2026-56358
CVSS base score
5.4 (v3.1)
Severity
MEDIUM
Attack vector
Network
Weakness
CWE-79
Last modified
October 29, 2026
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Affected products
n8n n8n
References
- github.com Mitigation, Vendor Advisory
- www.vulncheck.com Third Party Advisory