GHSA-g9hg-qhmf-q45m
Fix: modelcontextprotocol/inspector@650f309GHSA-g9hg-qhmf-q45m is a CWE-84 vulnerability in @modelcontextprotocol/inspector. O3 Security confirms whether GHSA-g9hg-qhmf-q45m is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
MCP Inspector is Vulnerable to Potential Command Execution via XSS When Connecting to an Untrusted MCP Server
Real-World Exposure
@modelcontextprotocol/inspectorReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects npm packages — download data is not available via public APIs for these ecosystems.
Description
An XSS flaw exists in the MCP Inspector local development tool when it renders a redirect URL returned by a remote MCP server. If the Inspector connects to an untrusted server, a crafted redirect can inject script into the Inspector context and, via the built-in proxy, be leveraged to trigger arbitrary command execution on the developer machine. Version 0.16.6 hardens URL handling/validation and prevents script execution.
Thank you to the following researchers for their reports and contributions:
- Raymond (Veria Labs)
- Gavin Zhong, [email protected] & Shuyang Wang, [email protected].
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @modelcontextprotocol/inspector | all versions | 0.16.6 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @modelcontextprotocol/inspector. 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 @modelcontextprotocol/inspector to 0.16.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-g9hg-qhmf-q45m 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-g9hg-qhmf-q45m 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-g9hg-qhmf-q45m. 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-g9hg-qhmf-q45m in your dependencies?
O3 detects GHSA-g9hg-qhmf-q45m across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.