GHSA-ph9w-r52h-28p7: langflow: /profile_pictures/{folder_name}/{file_name} endpoint file reading

Langflow's /profile_pictures/{folder_name}/{file_name} endpoint has a path traversal vulnerability (a flaw where attackers use ../ sequences to access files outside the intended directory). The folder_name and file_name parameters aren't properly validated, allowing attackers to read the secret_key file across directories. Since the secret_key is used for JWT authentication (a token system that verifies who you are), an attacker can forge login tokens and gain unauthorized access to the system.