GHSA-pq7c-x8g4-rvp6
MEDIUMGHSA-pq7c-x8g4-rvp6 is a medium-severity (CVSS 5.3) CWE-248 vulnerability in nicegui. O3 Security confirms whether GHSA-pq7c-x8g4-rvp6 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
NiceGUI: Unauthenticated log-volume denial of service in dynamic resource routes
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-pq7c-x8g4-rvp6.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-pq7c-x8g4-rvp6 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 360,142 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
niceguiReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Summary
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. There is no impact to confidentiality or integrity.
Details
The affected routes are the per-component resource route (added in v1.4.6) and the ESM module route (added in v3.0.0). Both join a user-supplied path segment with a registered base directory and pass the result to FileResponse. The existing existence check uses pathlib.Path.exists(), which returns True for directories — so a request whose sub-path resolves to a directory passes the guard and triggers an unhandled exception inside Starlette.
FastAPI has no default handler for RuntimeError, so each such request results in a 500 response and a multi-frame traceback in the server log.
Other NiceGUI-served paths (/static/..., /components/..., /libraries/...) are not affected; they do not use the same sub-path-to-FileResponse pattern.
Impact
A remote, unauthenticated attacker can repeatedly trigger the error condition with crafted requests. Each request emits roughly 100 lines of traceback in a default setup, and more when additional middleware layers are present. At sustained request rates this can:
- exhaust disk space on hosts with default log retention,
- saturate downstream log-shipping pipelines,
- generate alert fatigue or mask other events in monitoring.
There is no remote code execution, no path traversal, and no data exposure beyond the absolute installation path that already appears in any uncaught exception trace.
Workarounds
For deployments that cannot upgrade immediately:
- Place NiceGUI behind a reverse proxy that rejects requests where the path after
/_nicegui/<version>/esm/<key>/or/_nicegui/<version>/resources/<key>/is empty. - Rate-limit the
/_nicegui/prefix at the proxy. - Configure log rotation aggressively for the affected service.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | nicegui | all versions | 3.12.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for nicegui. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update nicegui to 3.12.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-pq7c-x8g4-rvp6 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-pq7c-x8g4-rvp6 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-pq7c-x8g4-rvp6. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-pq7c-x8g4-rvp6 in your dependencies?
O3 detects GHSA-pq7c-x8g4-rvp6 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.