CVE-2026-25732
NiceGUI's Path Traversal via Unsanitized FileUpload.name Enables Arbitrary File Write
Description
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.
How to fix CVE-2026-25732
To remediate CVE-2026-25732, upgrade the affected package to a fixed version below.
- —upgrade to 3.7.0 or later
- —upgrade to 3.7.0 or later
Is CVE-2026-25732 being exploited?
Low — EPSS is 1.4%, meaning exploitation activity has not been observed at scale.
Affected packages (2)
- from 0, < 3.7.0
- from 0, < 3.7.0
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N |