If you find a security vulnerability in MCP Server Tester, please report it privately.
Do not open a public GitHub issue. Email security@glean.com with:
- a description of the vulnerability
- steps to reproduce it
- the version affected (
npx mst --version) - any relevant logs, with credentials removed
Only the latest release is actively supported with security patches.
| Version | Supported |
|---|---|
| Latest | ✅ |
| Older | ❌ |
In scope:
- OAuth and token handling (
mst login,mst token, token storage) - Secrets:
--secrets-file,auth.accessTokenEnvand client credentials, and their redaction from stored results, reports and logs - The local MCP proxy that serves tool variants to clients (it listens on 127.0.0.1)
- Processes MST starts (stdio MCP servers, CLI clients) and plugins it loads. Both run with your privileges by design; a report should show MST running or exposing something you didn't configure.
Out of scope:
- Vulnerabilities in the MCP servers or clients you test with MST; report those to their maintainers
- Social engineering and denial of service
We follow coordinated disclosure. Once a fix is released, we publish a security advisory on this repository and credit the reporter, unless they prefer to stay anonymous.