MCP-Shield – Detect security issues in MCP servers
I noticed the growing security concerns around MCP (https://news.ycombinator.com/item?id=43600192) and built an open source tool that can detect several patterns of tool poisoning attacks, exfiltration channels and cross-origin manipulations. MCP-Shield scans your installed servers (Cursor, Claude Desktop, etc.) and shows what each tool is trying to do at the instruction level, beyond just the API surface. It catches hidden instructions that try to read sensitive files, shadow other tools' behavior, or exfiltrate data. Example of what it detects: - Hidden instructions…
MCP-Shield – Detect security issues in MCP servers launched on April 15, 2025 with 134 votes, #327 of 7,818 launches that month and more than 95% of that year's launches. The site was still online in September 2026, 1 year on.
In plain words
MCP-Shield is an open-source security scanning tool for Model Context Protocol servers used in applications like Cursor and Claude Desktop. It analyzes installed MCP servers to detect malicious patterns including tool poisoning attacks, hidden instructions targeting sensitive files, cross-origin manipulations, tool shadowing, and data exfiltration attempts. The tool examines instructions at a deeper level than API surfaces to identify suspicious behavior, helping developers identify security threats in their MCP server installations.
written from the facts on this page · September 2026
From the sources
Security scanner for MCP servers. Contribute to riseandignite/mcp-shield development by creating an account on GitHub.
MCP-Shield scans your installed MCP (Model Context Protocol) servers and detects vulnerabilities like tool poisoning attacks, exfiltration channels and cross-origin escalations. npx mcp-shield --path ~ /path/to/config.json With the --identify-asfrom github.com
In the maker’s words, at launch
I noticed the growing security concerns around MCP (https://news.ycombinator.com/item?id=43600192) and built an open source tool that can detect several patterns of tool poisoning attacks, exfiltration channels and cross-origin manipulations. MCP-Shield scans your installed servers (Cursor, Claude…
Does a similar job
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