A critical security flaw, tracked as CVE-2026-21858 (nicknamed "ni8mare"), has been discovered in the n8n workflow automation platform. The vulnerability puts approximately 100,000 servers at risk of Remote Code Execution (RCE).
The Risk
The "ni8mare" flaw allows unauthenticated attackers to gain full access to host machines. By exploiting how n8n processes webhooks, hackers can manipulate HTTP headers to overwrite internal application variables. This leads to arbitrary file reading and full system compromise without requiring login credentials.
How to Stay Safe
The vulnerability affects various older versions of the software. To secure your infrastructure, you must update n8n to version 1.121.0 or higher immediately.
Security researchers at The Register report that public-facing instances are high-priority targets. Ensure your deployment is patched to prevent unauthorized access and data breaches.
