CVE-2026-65597 in n8n
Summary
by MITRE • 07/22/2026
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.
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Analysis
by VulDB Data Team • 07/22/2026
This vulnerability exists in n8n versions prior to 1.123.64, 2.x prior to 2.29.8, and before 2.30.1, representing a critical DOM-based cross-site scripting flaw within the HTML preview functionality. The technical implementation fails to properly sanitize user-provided content when rendering execution outputs into an iframe with srcdoc attribute, specifically omitting the sandbox attribute that would normally prevent script execution. This design oversight creates a vector where malicious scripts can be injected and subsequently executed within the same origin context as the legitimate editor session.
The vulnerability operates through a sanitizer bypass mechanism that allows crafted payloads to evade content filtering systems. When victims open the HTML preview of a maliciously crafted workflow, the embedded script executes with the privileges and session context of the authenticated user. This same-origin execution model enables the malicious code to make authenticated API calls directly to the n8n server using the victim's active session cookies and authentication tokens.
The operational impact of this vulnerability is severe as it allows an attacker with a global:member privilege account to escalate their access within the system. This privilege level typically grants users the ability to create, modify, and execute workflows, making them capable of crafting malicious payloads that exploit this XSS flaw. Once executed, the script can perform actions such as reading sensitive workflow data, modifying existing workflows, creating new automated attack chains, or exfiltrating information from the n8n instance.
From a cybersecurity perspective, this vulnerability maps directly to CWE-79 (Cross-site Scripting) and specifically CWE-749 (Exposed Dangerous Method or Function) within the Common Weakness Enumeration framework. The ATT&CK framework categorizes this as T1566.001 (Phishing with Social Engineering) in the initial access phase, followed by T1059.007 (Scripting - JavaScript) for execution and potentially T1566.002 (Spearphishing via Service) if the attack targets specific users. The vulnerability demonstrates a classic case of insufficient input validation combined with improper output encoding in web applications.
The recommended mitigation strategy involves implementing proper content sanitization mechanisms that prevent script injection attempts, adding the sandbox attribute to all iframe elements containing user-generated content, and enforcing strict CSP (Content Security Policy) headers that restrict script execution within the application context. Additionally, users should be restricted from executing arbitrary HTML content in preview modes, and any user-provided content should be properly escaped or filtered before rendering. The vendor has addressed this issue in the patched versions by implementing comprehensive sanitization routines and enforcing proper sandboxing of iframe content to prevent unauthorized script execution.