n8n is an open source workflow automation platform. Prior to versions 1.123.18 and 2.5.0, a vulnerability in the file access controls allows authenticated users with permission to create or modify workflows to read sensitive files from the n8n host system. This can be exploited to obtain critical configuration data and user credentials, leading to complete account takeover of any user on the instance. This issue has been patched in versions 1.123.18 and 2.5.0.