Is CVE-2026-39844 actively exploited?

No active exploitation of CVE-2026-39844 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-39844 be exploited remotely?

Yes. CVE-2026-39844 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2026-39844?

CVE-2026-39844 has a CVSS score of 7.5 (HIGH).

HOME VULNERABILITIESCVE-2026-39844

HIGH

CVE-2026-39844

CWE-22Published: April 8, 2026· Updated: Apr 15, 2026

7.5

CVSS v3.1

EPSS:0.05%probability of exploitation in 30 daysPercentile:15.9th

Official 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.

NVD Source

Technical Analysis

CVE-2026-39844 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in full integrity compromise (data manipulation), with a CVSS base score of 7.5.