Ni8mare CVE-2026-21858

[mohamed3nan]

Hi @sudo_james

Have you read this topic?

Security Advisory: Security Vulnerability in n8n Versions 1.65-1.120.4

[cve-ls] We were made aware in November of a critical security vulnerability affecting n8n version 1.65-1.120.4. This has been fixed in n8n version 1.121.0 and released to our entire customer base on November 18, 2025. We’re reaching out to ensure self-hosted users have the information needed to secure their instances. What happened The reported vulnerability affects certain form-based workflows. A vulnerable workflow could grant access to an unauthenticated remote attacker. This could potent…

You can run this workflow template to scan your instance for potentially vulnerable workflows:

and other tips in the topic,

Hopefully this helps