CVE-2026-25732
NiceGUI's Path Traversal via Unsanitized FileUpload.name Enables Arbitrary File Write
NiceGUI is a Python-based UI framework. Prior to 3.7.0, NiceGUI's FileUpload.name property exposes client-supplied filename metadata without sanitization, enabling path traversal when developers use the pattern UPLOAD_DIR / file.name. Malicious filenames containing ../ sequences allow attackers to write files outside intended directories, with potential for remote code execution through application file overwrites in vulnerable deployment patterns. This design creates a prevalent security footgun affecting applications following common community patterns. Note: Exploitation requires application code incorporating file.name into filesystem paths without sanitization. Applications using fixed paths, generated filenames, or explicit sanitization are not affected. This vulnerability is fixed in 3.7.0.
- Affected
- zauberzeug · nicegui
- CVSS v3.1 GITHUB
- 7.5 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N - EPSS
- 3.28% chance of exploitation in the next 30 days, 88th percentile
- Published
- 2026-02-06
- Updated
- 2026-02-09
Proof-of-concept exploits (2)
ExploitDB entries (1)
Security advisories
- zauberzeug/nicegui/security/advisories/GHSA-9ffm-fxg3-xrhh
- zauberzeug/nicegui/blob/main/nicegui/elements/upload_files.py#L79-L82