CVE-2026-45554 PUBLISHED

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

Assigner: GitHub_M
Reserved: 12.05.2026 Published: 02.06.2026 Updated: 02.06.2026

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.

Metrics

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
CVSS Score: 5.3

Product Status

Vendor zauberzeug
Product nicegui
Versions
  • Version < 3.12.0 is affected

References

Problem Types

  • CWE-248: Uncaught Exception CWE
  • CWE-770: Allocation of Resources Without Limits or Throttling CWE