HIGHVulnerability
Verified
Global

NVD HIGH: CVE-2026-39844 — NiceGUI is a Python-based UI framework. Prior to 3.10.0, Since PurePosixPath onl...

·Source: NIST NVD

Updated:

Executive Summary

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

Analysis

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. CVSS Score: 5.9. Published: 2026-04-08T21:16:59.883.

Indicators of Compromise (1)

CVE (1)
CVE-2026-39844
NVDMITRE CVE
Source Attribution

Originally published by NIST NVD on Apr 8, 2026. Verified by: NIST.

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