Check MCP Inspector security fixes before connecting

MCP Inspector's 2026-10-21 advisories describe remote servers or apps triggering local command execution ^[1]^[2]^[3]. Check the installed version before connecting it to an unfamiliar server.

Match your version to the advisory

The OAuth callback advisory lists versions 0.13.0 through 1.0.2 as affected and 1.0.3 as patched. It describes a remote server changing the connection transport during authorization ^[1].

The remote MCP App advisory lists versions 0.20.0 through 1.0.2 as affected, also patched in 1.0.3. It describes an app obtaining the proxy token and reaching local command execution ^[2].

For the v2 line, the Windows and WSL advisory covers 2.0.0 through 2.11.0 and lists 2.12.0 as patched. That issue can trigger during connection through the server's authorization URL ^[3]. These are fixes for the named advisories, not a guarantee against every vulnerability.

Choose the maintained release line

The repository says its main line tracks released v2, while v1 receives security fixes. Its documented web launcher is ^[4]:

bash

npx @modelcontextprotocol/inspector

Warning: Moving from v1 to v2 changes CLI flags, configuration and Node requirements. Read the migration guide linked from the README before replacing an existing setup ^[4].

If you need the maintained v1 line, the repository documents this separate tag ^[4]:

bash

npx @modelcontextprotocol/inspector@v1-latest

Confirm the resolved package version against the advisories before connecting. Do not assume a saved launcher command proves which version you have.

Review stored credentials

The README says Inspector stores secrets in the OS keychain when available. Without one, it can use ~/.mcp-inspector/secrets.json, unencrypted unless you supply a key. Follow its linked storage instructions before entering credentials ^[4].

You now have the affected ranges and release paths needed to check your setup before opening a connection.