N8n EUVD-2026-15945

Authenticated user with permission to create or modify workflows in n8n versions prior to 2.14.1, 2.13.3, or 1.123.27. Attacker crafts malicious parameters in XML or GSuiteAdmin node configuration to pollute Object.prototype and achieve RCE.

This vulnerability presents a high real-world risk despite requiring authentication. The CVSS 4.0 vector (AV:N/AC:L/PR:L) indicates network-accessible exploitation with low complexity and minimal privileges, making it straightforward to exploit once an attacker has basic authenticated access. The ability to achieve remote code execution elevates this from a theoretical concern to a critical operational risk, particularly in multi-tenant or shared n8n instances where workflow permissions may be broadly distributed. The impact scores (VC:H/VI:H/VA:H/SC:H/SI:H/SA:H) indicate complete compromise of confidentiality, integrity, and availability across both the vulnerable system and subsequent systems. While no EPSS score, KEV listing, or public POC is provided in the intelligence, the straightforward nature of prototype pollution exploitation in Node.js environments and the direct path to RCE suggest this vulnerability will be actively targeted once details become public. Organizations using n8n should treat this as an urgent patching priority, especially those with untrusted or semi-trusted users having workflow permissions.

An authenticated attacker with workflow creation privileges logs into an n8n instance and creates a new workflow containing an XML or GSuiteAdmin node. The attacker crafts malicious node configuration parameters containing prototype pollution payloads (such as __proto__ or constructor.prototype property paths) that inject attacker-controlled values onto Object.prototype. When the workflow executes, the polluted prototype properties are leveraged by subsequent n8n operations to execute arbitrary code on the n8n server, granting the attacker full control over the instance and access to all workflow data, credentials, and connected systems.