CVE-2026-39844

MEDIUM

5.9

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.

CVE Details

CVSS v3.1 Score5.9

SeverityMEDIUM

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

Attack VectorNETWORK

ComplexityHIGH

Privileges RequiredNONE

User InteractionNONE

Published4/8/2026

Last Modified4/8/2026

Sourcenvd

Honeypot Sightings0

Weaknesses (CWE)

CWE-22

References

https://github.com/zauberzeug/nicegui/commit/d38a702e3af2da5b0708f689be8d71413fc77056(security-advisories@github.com)

https://github.com/zauberzeug/nicegui/releases/tag/v3.10.0(security-advisories@github.com)

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

IOC Correlations

No correlations recorded

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