CVE-2026-25732
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (3.34%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- EPSS
- 3.34% probability · 88th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-22
- Affected
- zauberzeug/nicegui
- Source
- security-advisories@github.com
References
- https://github.com/zauberzeug/nicegui/blob/main/nicegui/elements/upload_files.py#L110-L115Patch
- https://github.com/zauberzeug/nicegui/blob/main/nicegui/elements/upload_files.py#L79-L82Patch
- https://github.com/zauberzeug/nicegui/security/advisories/GHSA-9ffm-fxg3-xrhhExploit, Mitigation, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.