CVE-2026-25732: CVE-2026-25732: NiceGUI is a Python-based UI framework. Prior to 3.7.0, NiceGUI's FileUpload.name property…
zauberzeug · nicegui · NVD published 2026-02-07 · posted 2026-04-30 · last modified 2026-06-17
What it is
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.
| Weakness | CWE-22 |
|---|---|
| CVSS vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N (source: [email protected]) |
| ATT&CK tactics | Initial Access → Execution → Discovery |
Exploitation evidence
First exploit evidence seen: 2026-04-30 (earliest date across the sources below).
Exploited in the wild
No source on this site lists in-the-wild exploitation yet (CISA KEV, VulnCheck KEV).
Public exploit code
Exploit-DB
- EDB-52534: NiceGUI 3.6.1 - Path Traversal (2026-04-30)
GitHub proof-of-concept repositories below quality bar
1 public repositories from 1 accounts, first seen 2026-02-08.
Verify before running: public PoCs can be malicious. Read the code and only run it in an isolated lab. A PoC means exploit code is public, not that this CVE is exploited in the wild.
Sources: Exploit-DB (OffSec) · nomi-sec/PoC-in-GitHub.
Defend the Chain
The attack chain for CVE-2026-25732 laid across the MITRE ATT&CK Enterprise tactics. Solid cards come from the MITRE CTID KEV mappings; dashed cards are inferred by CVERadar from the CWE or description. Correct defences are real ATT&CK mitigations for that technique.
Pick a red technique card on the board, then choose the defence that stops it.
Defend against T1190 Exploit Public-Facing Application Inferred
Inferred from CWE CWE-22
How to fix it
Fixed versions
- zauberzeug nicegui: upgrade to 3.7.0 or later
Derived from the NVD CPE configuration (versionEndExcluding / versionEndIncluding). Always confirm with the vendor advisory.
Vendor advisories and patches
- https://github.com/zauberzeug/nicegui/blob/main/nicegui/elements/upload_files.py#L110-L115 (Patch)
- https://github.com/zauberzeug/nicegui/blob/main/nicegui/elements/upload_files.py#L79-L82 (Patch)
- https://github.com/zauberzeug/nicegui/security/advisories/GHSA-9ffm-fxg3-xrhh (Exploit, Mitigation, Vendor Advisory)
MITRE ATT&CK mitigations for this chain
- M1048 Application Isolation and Sandboxing (for T1190, T1203) : Application isolation will limit what other processes and system features the exploited target can access.
- M1037 Filter Network Traffic (for T1190) : Restrict outbound network traffic from public-facing servers to prevent unauthorized connections from initiating communications with attacker-controlled infrastructure. While this may not prevent the initial exploitation, it limits the attacker's ability to verify and control the compromised server post-exploit, reduci
- M1030 Network Segmentation (for T1190) : Segment externally facing servers and services from the rest of the network with a DMZ or on separate hosting infrastructure.
- M1016 Vulnerability Scanning (for T1190) : Regularly scan externally facing systems for vulnerabilities and establish procedures to rapidly patch systems when critical vulnerabilities are discovered through scanning and through public disclosure.
- M1026 Privileged Account Management (for T1190) : Use least privilege for service accounts will limit what permissions the exploited process gets on the rest of the system.
- M1050 Exploit Protection (for T1190, T1203) : Web Application Firewalls may be used to limit exposure of applications to prevent exploit traffic from reaching the application.
- M1035 Limit Access to Resource Over Network (for T1190) : Ensure that all publicly exposed services are actually intended to be so, and restrict access to any that should only be available internally.
- M1051 Update Software (for T1190, T1203) : Update software regularly by employing patch management for externally exposed applications.
Detection Generic guidance
- Initial Access: Alert on unusual requests to the affected service (odd paths, oversized payloads, exploit strings) in WAF, reverse-proxy and application logs.
- Execution: Watch for the service process spawning shells or script interpreters (cmd.exe, powershell, sh, bash, python) via EDR process-tree rules.
- Discovery: Look for directory listing, file enumeration and reconnaissance commands from service accounts.
Response checklist Generic guidance
- Inventory: find every instance of the affected product and version (include internet-facing and forgotten ones).
- Patch or mitigate per the vendor advisory; if you cannot patch, remove internet exposure or apply the vendor workaround.
- Assume compromise if the system was exposed before patching: hunt for the indicators in the advisory and review logs back to the disclosure date.
- Rotate credentials and secrets stored on or used by the affected system if compromise cannot be ruled out.