CVE-2026-45554 MEDIUM

CVE-2026-45554: NiceGUI: Unauthenticated log-flood DoS via trailing slash on ESM and per-component resource routes

Vendor Zauberzeug
Product nicegui
Weakness CWE-248
Published June 2, 2026
Last update June 2, 2026

CVSS base score

5.3/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality None
Integrity None

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

What the vulnerability does

01Description

NiceGUI is a Python-based UI framework. Prior to version 3.12.0, two FastAPI routes that serve per-component static assets in NiceGUI accept a sub-path parameter that may resolve to a directory rather than a file. Requests that resolve to a directory raise an unhandled RuntimeError inside Starlette's FileResponse, which Uvicorn writes to the server log as a full traceback. Because the routes are reachable without authentication, a remote attacker can amplify log volume and consume disk and log-pipeline capacity on any publicly reachable NiceGUI server. This issue has been patched in version 3.12.0.

Key dates

02Disclosure timeline

June 2, 2026 CVE published
June 2, 2026 Record updated