CVE-2026-39844

Publication date

2026-04-08 20:13:31

Family

GitHub_M

State

PUBLISHED

Description

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 demonstrated in NiceGUIs bundled examples) are vulnerable to arbitrary file write on Windows. This vulnerability is fixed in 3.10.0.