NiceGUI is a Python-based UI framework.

Code

The project this record applies to. Exploit listings stay in References.

• Repository · github.com

Timeline

Detection, updates, and resolution for this record.

1. Apr 8, 2026 · NIST NVD

   Detected

   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

2. Jul 24, 2026 · NIST NVD

   Updated

   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

Affected

• cpe zauberzeug/niceguiversion unspecified

Sources

• CVE.orgVulnerability recordCVE-2026-39844

  Official CVE identifier

  cve.org
• NIST NVDVulnerability recordCVE-2026-39844

  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 f

  nvd.nist.gov

References

• Patch · github.com
• Release Notes · github.com
• Vendor Advisory · github.com