GHSA-wg2q-39h6-66x9: goshs has a Path Traversal issue

The goshs software has a path traversal vulnerability (a security flaw where attackers can access files outside the intended directory) in its file upload feature. The code splits filenames on path separators but fails to reject ".." (a notation that means "parent directory"), allowing an unauthenticated attacker to write files outside the web server's intended directory with a simple filename like "..".