CVE-2025-66645: NiceGUI Path Traversal Vulnerability in app.add_media_files() Allows Arbitrary File Reading

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.1% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2025-12-09 · updated 2026-10-14
Weakness: CWE-22

Description

NiceGUI is a Python-based UI framework. Versions 3.3.1 and below are vulnerable to directory traversal through the App.add_media_files() function, which allows a remote attacker to read arbitrary files on the server filesystem. This issue is fixed in version 3.4.0.

Affected products

zauberzeug nicegui: before 3.4.0 — fixed in 3.4.0

How to fix

Upgrade to a fixed version: zauberzeug nicegui 3.4.0. Check the vendor advisory for mitigations.

References

https://github.com/zauberzeug/nicegui/commit/a1b89e2a24e1911a40389ace2153a37f4eea92a9
https://github.com/zauberzeug/nicegui/security/advisories/GHSA-hxp3-63hc-5366
https://github.com/zauberzeug/nicegui/security/advisories/GHSA-hxp3-63hc-5366

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