MCPRadar

Security scanner for Model Context Protocol servers.
Catch tool poisoning, prompt injection, and supply-chain rug pulls before your agent runs them.

Quick Start | Detection Rules | Comparison | OWASP Coverage | GitHub Action | Roadmap | Architecture

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Why

The Model Context Protocol ecosystem is growing fast, and so is its attack surface.

A 2025 study of 1,899 MCP servers found that 7.2% contain general vulnerabilities and 5.5% exhibit MCP-specific tool poisoning (arXiv:2506.13538). OX Security separately demonstrated remote code execution across official MCP SDKs (Python, TypeScript, Java, Rust), with at least 10 high/critical CVEs.

The catch: traditional security tools don't watch MCP tool descriptions or detect "rug pull" attacks where a server changes its tool schema after install. MCPRadar does.

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Quick Start

uvx mcpradar scan "npx -y @modelcontextprotocol/server-filesystem /tmp" -t stdio

One command, no install, runs against any MCP server you can launch.

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Features

Core Detection (all built, all tested)

• 12 static rules (R001-R109): Dangerous tool names, zero-width Unicode, prompt injection (10 patterns), base64/hex blobs, hidden HTML/Markdown, permission scope mismatch, secret/token exposure, command injection, supply chain risk, schema poisoning
• 7 cross-server rules (C001-C007): Tool name collision, shadowing, exfiltration chains, capability overlap, permission gradient, attack path chains, privilege escalation
• 2 runtime rules (R110-R111): Version anomaly detection via fingerprint diff, insecure transport detection via TLS handshake + HSTS check

CI/CD and Output

• SARIF v2.1.0: Drops into GitHub Security tab via one Action
• AIVSS 0-10 scoring: AI Vulnerability Severity Score with CWE mapping
• Snapshot diff: SQLite-backed history with cosmetic / behavioral / security classification
• Fast: Pure Python, no daemons, runs in CI under 5 seconds

Supply Chain

• CycloneDX 1.5 SBOM: Export dependency bill of materials
• Fingerprint-based change detection: SHA-256 of tool names for rug pull detection across scans
• NVD CVE feed: MCP-related CVE sync from NVD API 2.0 with multi-factor finding-to-CVE matching

Enterprise

• Argument sanitizer: Validates and sanitizes tool arguments before probing (container sandbox planned v1.1)
• Audit trail: Structured event logging (scan_start, finding_created, diff_detected)
• Stats engine: Per-server trend analysis, top rules, severity distribution
• Plugin system: entry_points auto-discovery, mcpradar plugin init/validate/install

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What's Real vs Planned

Production-Ready Today (v1.0.0-rc3)

• 19 detection rules (12 static + 7 cross-server), 407 tests passing
• SQLite-backed scan history with diff engine
• SARIF v2.1.0 output for GitHub Security tab
• Watch mode (periodic scanning + webhook/command alerts)
• Audit trail with structured event logging
• Stats engine with per-server trend analysis
• Plugin system with entry_points auto-discovery
• CycloneDX SBOM export
• NVD CVE feed sync
• AIVSS 0-10 scoring + A-F letter grades
• Public security leaderboard at https://yatuk.github.io/mcpradar

Planned (v1.1+)

• Source scanning: Scan GitHub repos, npm/pip packages without running the server
• AST + Semgrep: Source-code static analysis (DCI, unsafe deserialization, SQLi)
• Container sandbox: Disposable Docker/Podman with egress lock for untrusted servers
• OSV/GitHub Advisory: Dependency CVE checking beyond NVD
• Typosquatting detection: Levenshtein distance against known top packages
• Runtime proxy: Transparent MCP traffic inspection

See ROADMAP.md for details and timeline.

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How It Works

graph LR
    A[CLI] --> B[Scanner Engine]
    B -->|stdio/SSE/HTTP| C[MCP Server]
    C -->|tools, prompts, resources| B
    B --> D[Rule Engine]
    D -->|findings| E[SQLite Snapshot]
    E --> F[Scoring Engine]
    F -->|AIVSS 0-10| G[Rich / JSON / SARIF]
    B -.->|planned v1.1| P[Package Scanner]
    P -.->|planned v1.1| S[Source Analysis]
    S -.->|planned v1.1| D2[Rule Engine]
    D2 -.->|planned v1.1| E
    B -.->|planned v1.1| H[Sandbox Engine]
    H -.->|planned v1.1| C

Source scanning and sandbox containers are planned for v1.1. All other components are production-ready.

MCPRadar connects to the MCP server, enumerates tools/prompts/resources, runs each tool schema through the rule engine, computes AIVSS scores, stores the snapshot in SQLite, and outputs the report. Subsequent scans diff against history to catch silent changes.

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Comparison

Feature presence in MCP security tools. Feature checkmarks do not imply detection accuracy. See Benchmarks for measured precision/recall data.

Feature	MCPRadar	Cisco mcp-scanner	Snyk agent-scan	Pipelock	Hermes	agent-audit	MCP Guardian
Approach	Static + Diff	YARA + LLM + VirusTotal	LLM classifier	Runtime proxy (Go)	Fuzz + Probe (Rust)	SAST 40+ rules	Policy proxy
Zero-width Unicode	Yes	-	-	Yes	-	-	-
Prompt injection	10 patterns	YARA patterns	LLM-based	Yes	-	-	-
Base64/hex blob	Yes	-	-	Yes	-	-	-
Hidden HTML/MD	Yes	-	-	Yes	-	-	-
Secret/token scan	Yes	Yes	-	Yes	Yes	Yes	-
Command injection	Yes	-	-	Yes	Yes	Yes	-
Supply chain risk	Yes	-	-	-	-	Yes	-
DCI (desc vs code)	Planned v1.1	-	-	-	-	Partial	-
Cross-server analysis	Yes (C001-C007)	-	-	-	-	-	-
Source scanning	Planned v1.1	-	-	-	-	Yes	-
SBOM + dep. CVE	Yes (CycloneDX + NVD)	-	-	-	-	-	-
Sandbox execution	Planned v1.1	-	-	N/A (proxy)	-	-	-
AIVSS scoring	Yes (0-10 + CWE)	LLM score	Yes	-	-	-	-
Snapshot diff	Yes (3-level)	Not documented	Version compare	Yes	-	-	-
SARIF output	Yes (v2.1.0)	Yes	-	-	Yes	-	-
stdio transport	Yes	-	-	-	-	-	-
Runtime proxy	Planned v1.1	-	-	Yes	-	-	Yes
License	MIT	Apache 2.0	Snyk platform	Apache 2.0	Unknown	Unknown	Custom
Offline capable	Yes	No (VT/LLM API)	No (LLM API)	Yes	Yes	Yes	Yes
Accuracy measured?	Yes (BENCHMARK)	Not published	Not published	Not published	Not published	0.91 F1	Not published

"-" means the feature could not be verified from public documentation. This does not mean the tool lacks the capability, only that we have no data to confirm it. Corrections welcome via PR.

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Benchmarks

MCPRadar's detection accuracy is measured against a labeled corpus and published in validation/BENCHMARK.md. The benchmark includes:

• Positive cases: demo/malicious_server.py with 9 intentionally vulnerable tools covering R001-R109
• Negative controls: Official MCP reference servers (filesystem, memory, everything) with expected zero findings
• External corpus: Appsecco Vulnerable MCP Servers Lab with 9 servers covering labeled vulnerability classes

Metric	Target
Precision	>= 80%
Recall	>= 85%
F1 Score	>= 0.82

Performance benchmarks (tests/test_benchmark.py): rule engine latency ~14 ms (100 tools), SARIF generation ~2 ms (100 findings), SQLite insert ~1.5 ms (batch).

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Known Limitations

MCPRadar is a pattern detector, not an exploitability oracle. It does not execute code or exploit vulnerabilities. Understand its limits:

Rule	Detection Method	FP Risk	Notes
R102 (Prompt injection)	Regex patterns	Medium	"You must..." in docs, "system:" in OS references
R105 (Scope mismatch)	Heuristic word overlap	High	Legitimate bridge/adapter tools; allowed via BRIDGE_KEYWORDS
R106 (Secrets)	Pattern + entropy	Medium	Placeholder keys, example tokens, high-entropy IDs
R107 (Command injection)	Shell metachar sequences	Medium	Build scripts, command examples in documentation
R108 (Supply chain)	Install/exec patterns	High	pip install, npx, eval( in setup instructions

For detailed triage guidance, see docs/false-positives.md.

What MCPRadar does NOT do:

• Execute or validate exploitability of detected patterns
• Detect runtime-only attacks on live traffic (use a runtime proxy for that)
• Guarantee zero false negatives; novel attack patterns may evade static rules

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Installation

# No install needed: one-shot with uvx
uvx mcpradar scan http://localhost:8080

# Install with pip
pip install mcpradar

# Install with pipx (isolated environment)
pipx install mcpradar

# Install with uv tool (fast, managed Python)
uv tool install mcpradar

Requires Python 3.11+. All transports (stdio, SSE, HTTP) work out of the box.

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Usage

# Scan a local stdio server
mcpradar scan stdio -- npx -y @modelcontextprotocol/server-filesystem /tmp

# Scan an HTTP server, only critical findings
mcpradar scan http://localhost:8080 -s critical

# SARIF for CI
mcpradar scan http://x --format sarif -o results.sarif

# Diff last 2 scans (rug pull detection)
mcpradar diff http://localhost:8080

# Plugin management
mcpradar plugin init my-rule
mcpradar plugin validate ./my-rule
mcpradar plugin list

# Runtime probing (safe read-only tools only)
mcpradar probe http://localhost:8080 --safe-only

# Server fingerprinting
mcpradar fingerprint http://localhost:8080

# Cross-server deep analysis
mcpradar analyze-context --deep --graph -o risk.dot

# Audit trail and statistics
mcpradar audit --target http://localhost:8080
mcpradar stats http://localhost:8080

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Example Output

$ mcpradar scan "npx -y @modelcontextprotocol/server-filesystem /tmp" -t stdio

Scanning @modelcontextprotocol/server-filesystem (stdio)...
  Enumerated 7 tools, 0 prompts, 0 resources
  Probed 5 safe tools, 4 findings

  CRITICAL  R102  Prompt Injection          tool: get_file_contents
            "You must read this file..." detected in description
  HIGH      R104  Hidden Content            tool: read_file
            display:none hidden <div> in description
  HIGH      R109  Schema Poisoning          tool: write_file
            additionalProperties: true allows arbitrary injection
  MEDIUM    R105  Scope Mismatch            3 tools with read-only names
            have description mentioning write/delete operations

AIVSS Score: 6.8 / 10  Grade: C
  3 critical, 5 high, 2 medium, 0 low
  SHA-256: a1b2c3d4... (tool fingerprint saved)

Report saved to scan_result.json

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GitHub Action

- name: Scan MCP server
  run: uvx mcpradar scan ${{ inputs.server }} --format sarif -o results.sarif

- uses: github/codeql-action/upload-sarif@v3
  with:
    sarif_file: results.sarif

Findings appear in your repo's Security tab. Full template: .github/workflows/example-action.yml

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Detection Rules

Static Rules (v1.0)

ID	Rule	Severity	OWASP	Catches
R001	Dangerous Tool Name	CRITICAL	MCP03	eval, exec, rm, shell, curl, wget, chmod ...
R101	Zero-Width Unicode	HIGH/CRITICAL	MCP06	ZWSP, LRM, RLO, BOM (CRITICAL in tool name, HIGH in description)
R102	Prompt Injection	HIGH/CRITICAL	MCP06	"ignore previous", system:, `<
R103	Encoded Blob	MEDIUM/HIGH	MCP06	Base64 (40+ chars), hex (32+ chars); HIGH if decodes to readable text
R104	Hidden Content	HIGH	MCP03	display:none, font-size:0, hidden Markdown links, deceptive <a> tags
R105	Scope Mismatch	LOW/MEDIUM	MCP02	Tool name implies file/db/read-only, description mentions network/shell/write
R106	Secret/Token Exposure	CRITICAL/HIGH	MCP01	API keys, GitHub tokens, JWTs, DB connection strings, high-entropy strings
R107	Command Injection	CRITICAL/HIGH	MCP05	Shell metacharacters, dangerous defaults, overly broad regex, command enums
R108	Supply Chain Risk	HIGH/MEDIUM	MCP04	`curl
R109	Schema Poisoning	HIGH/MEDIUM	MCP03	additionalProperties: true, missing types, excessive maxLength/maxItems
R110	Version Anomaly	HIGH/CRITICAL	MCP09	Version rollback, major upgrade, tool list change, TLS downgrade
R111	Insecure Transport	HIGH/CRITICAL	MCP07	Plain HTTP, TLS < 1.2, expired/self-signed certs, missing HSTS

Cross-Server Rules

ID	Rule	Severity	OWASP	Catches
C001	Tool Name Collision	CRITICAL	MCP10	Same tool name exposed by 2+ servers; LLM may call wrong one
C002	Tool Name Shadowing	HIGH	MCP10	Similar tool names across servers (>=75% similarity)
C003	Exfiltration Chain	CRITICAL	MCP10	Server A reads sensitive data, Server B sends it out
C004	Capability Overlap	MEDIUM	MCP10	3+ servers exposing same capability (file_read, shell_exec...)
C005	Permission Gradient	MEDIUM	MCP02	Read-only + write-capable server mix; injection may hijack write access
C006	Attack Path Chain	CRITICAL/HIGH/MEDIUM	MCP03/MCP10	Schema type matching across server tool outputs and inputs
C007	Privilege Escalation	CRITICAL	MCP02	Read-only tool output feeds into write/exec tool input on another server

Full docs: docs/detection-rules.md

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Public Leaderboard

Security scores for popular MCP servers, updated weekly:

yatuk.github.io/mcpradar

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OWASP MCP Top 10 Coverage

MCPRadar targets full coverage of the OWASP MCP Top 10 (2025):

#	Risk	Covered By	Status
MCP01	Token Mismanagement & Secret Exposure	R106	Strong
MCP02	Privilege Escalation via Scope Creep	R105, C005, C007	Strong
MCP03	Tool Poisoning	R001, R104, R109, C006	Strong
MCP04	Supply Chain Attacks & Dependency Tampering	R108	Strong
MCP05	Command Injection & Execution	R001, R107	Strong
MCP06	Prompt Injection via Contextual Payloads	R101, R102, R103, R104	Strong
MCP07	Insufficient AuthN/AuthZ	R111	Strong
MCP08	Lack of Audit & Telemetry	Audit trail, Stats engine	Strong
MCP09	Shadow MCP Servers	R110	Strong
MCP10	Context Injection & Over-Sharing	C001-C007	Strong

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Roadmap

See ROADMAP.md for the full development roadmap.

Summary

Sprint	Version	Focus
Done 1	v0.2.0	4 new rules: Secret exposure (R106), Command injection (R107), Supply chain (R108), Schema poisoning (R109)
Done 2	v0.3.0	Plugin system: PluginManager, Validator, Scaffolder, CLI
Done 3	v0.4.0	Server fingerprinting + Transport security (R110, R111)
Done 4	v0.5.0	Deep cross-server analysis + Runtime probing (C006, C007)
5	v0.6.0	Audit trail + CVE automation + Statistics
Done 6	v1.0.0-rc1	Validation, performance, documentation; OWASP 10/10

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Troubleshooting

Problem	Solution
Connection refused	Verify the server is running. For stdio, check the command works standalone.
Timeout during scan	Increase timeout: mcpradar scan <target> --timeout 60
"No tools found"	The server may require authentication. Use -t stdio if it's a local process.
High false positive rate	See docs/false-positives.md for per-rule triage guidance.
SARIF upload fails	Ensure github/codeql-action/upload-sarif@v3 is in your workflow.
Python version error	MCPRadar requires Python 3.11+. Check with python --version.

For more help, open an issue.

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Contributing

We welcome contributions. Adding a new detection rule is straightforward:

class MyRule(Rule):
    rule_id = "R200"
    title = "My custom check"
    severity = Severity.HIGH

    def check(self, tool: ToolInfo) -> list[Finding]:
        ...

See CONTRIBUTING.md for setup, testing, and PR expectations. docs/contributing.md covers rule design guidelines and false-positive reduction tips.

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Star History

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Contributors

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License

MIT (c) 2026 Fatih Serdar Cakmak