Path handling is the code that turns a user-supplied location into a real file path. It decides whether a request points to a safe file, a forbidden directory, or a traversal attempt such as ../ sequences. Good path handling normalizes input, rejects unexpected separators and encodings, and enforces an allowlist or sandbox before opening a file.
In cyber security, weak path handling often leads to arbitrary file read, file overwrite, or even code execution if an attacker can reach sensitive configuration or templates. It matters in self-hosted platforms because reading logs, keys, or service files can expose secrets and internal routes. Defenders look for canonicalization bugs, symlink confusion, and missing boundary checks; attackers look for paths that bypass validation and escape the intended directory. Strong path handling is a basic control that can turn a dangerous file-access bug into a harmless request.