CVE-2026-39844EPSS p39.8%
CVE-2026-39844CVE-2026-39844
zauberzeug / nicegui
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 NiceGUI's bundled examples) are vulnerable to arbitrary file write on Windows. This vulnerability is fixed in 3.10.0.
Scoring
| CVSS | 5.9 () |
| Vector | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N |
| EPSS | 0.49% probability of exploitation · percentile 39.8% · 2026-10-05T12:00:23Z |
| Last modified | 2026-07-24 |