Critical Vulnerabilities Uncovered in n8n Platform

Security researchers have uncovered multiple critical vulnerabilities in n8n, a popular open-source workflow automation platform used by millions to connect applications and automate tasks, potentially allowing attackers to execute arbitrary code and access sensitive enterprise data. The most severe flaw, dubbed Ni8mare and tracked as CVE-2026-21858, carries a maximum CVSS score of 10.0 and enables unauthenticated remote attackers to read arbitrary files on affected servers, leading to full system compromise.

The Ni8mare vulnerability stems from improper handling of HTTP requests in n8n's webhook and form processing logic. According to a report from data security firm Cyera, which discovered the issue, the platform fails to properly validate the Content-Type header in certain scenarios. When a request mimics a multipart/form-data upload but uses a different content type, such as application/json, attackers can manipulate the request to control file metadata and paths. This tricks n8n into copying local system files, such as configuration files or databases, instead of processing legitimate uploads. Downstream workflow nodes then expose the contents, allowing extraction of...