CVE-2026-39844 NiceGUI has a Path Traversal in NiceGUI Upload Filename on Windows via Backslash Bypass of PurePosixPath Sanitization

NiceGUI is a Python-based UI framework. Prior to 3.10.0, Since PurePosixPath only recognizes forward slashes / as path separators, an attacker can bypass this sanitization on Windows by using backslashes \ in the upload filename. Applications that construct file paths using file.name a pattern...