CVE-2026-39844

medium

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.

References

https://github.com/zauberzeug/nicegui/security/advisories/GHSA-w8wv-vfpc-hw2w

https://github.com/zauberzeug/nicegui/releases/tag/v3.10.0

https://github.com/zauberzeug/nicegui/commit/d38a702e3af2da5b0708f689be8d71413fc77056

Details

Source: Mitre, NVD

Published: 2026-04-08

Updated: 2026-04-08

Risk Information

CVSS v2

Base Score: 5.4

Vector: CVSS2#AV:N/AC:H/Au:N/C:N/I:C/A:N

Severity: Medium

CVSS v3

Base Score: 5.9

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N

Severity: Medium

EPSS

EPSS: 0.00051