WPvivid Backup & Migration < 0.9.137 - Admin+ Path Traversal via Staging Site Path

Description

The plugin does not sanitize the staging destination folder supplied to its staging-start handler, applying only a generic text filter while the sibling writability-check handler applies the correct filename sanitizer, so an authenticated administrator can supply a path containing traversal sequences and make the plugin write the copied site files outside the WordPress installation directory.