CVE-2026-45554 json
NiceGUI: Unauthenticated log-flood DoS via trailing slash on ESM and per-component resource routes
published 5mo ago modified 3mo ago also EUVD-2026-33965 , GHSA-pq7c-x8g4-rvp6 , PYSEC-2026-2680
- cvss
- 5.3
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 28%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- pypi nicegui 3.12.0
- zauberzeug nicegui 3.12.0
Is CVE-2026-45554 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerCISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 5mo ago
Exploit prediction
0.34% chance of exploitation in the next 30 days, higher than 28% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L |
| GitHub | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L |
| OSV | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| pypi | nicegui | <3.12.0 |
3.12.0 |
Affected products
- zauberzeug nicegui
Classification
References
-
github.com
/zauberzeug/nicegui/security/advisories/GHSA-pq7c-x8g4-rvp6
web
-
github.com
/zauberzeug/nicegui/releases/tag/v3.12.0
web
-
nvd.nist.gov
/vuln/detail/CVE-2026-45554
advisory
-
github.com
/zauberzeug/nicegui
package
-
pypi.org
/project/nicegui
package
-
github.com
/advisories/GHSA-pq7c-x8g4-rvp6
advisory
Sources
- CVE List CVE-2026-45554
- GitHub Advisory GHSA-pq7c-x8g4-rvp6
- NVD CVE-2026-45554
- OSV PYSEC-2026-2680
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.