MCP Security Scanner Comparison 2026
Signal Sentinel vs Other MCP Scanners
Signal Sentinel Scanner has 49 security rules across four scan surfaces, triple OWASP mapping, SARIF output, policy presets and offline mode – the most comprehensive open-source MCP and Agent Skill security scanner available. Here is how it compares.
Full feature comparison
Last updated September 2026. Based on publicly available documentation for each tool.
| Feature | Signal Sentinel v3.1.0 | Invariant MCP Scan | Pillar MCP Audit |
|---|---|---|---|
| Detection | |||
| Security Rules | 49 (42 detection + 7 informational) | ~5 | ~3 |
| Scan Surfaces | MCP servers, Agent Skills, MCP server source, A2A Agent Cards | MCP servers | MCP servers |
| Agent Skill Scanning | Yes (SKILL.md + bundled scripts) | None | None |
| MCP Server Source Analysis | Yes (--server-source) | No | No |
| A2A Agent Card Evaluation | Yes (--agent-card) | No | No |
| SkillJacking Detection | Yes (SS-029) | No | No |
| Skill Dependency CVE Lookup | Yes (--osv, opt-in) | No | No |
| MCP Spec Currency Tracking | Yes (SS-INFO-004) | No | No |
| OWASP | |||
| OWASP Agentic AI Top 10 (ASI) | Full (ASI01–ASI10) | Partial | None |
| OWASP Agentic Skills Top 10 (AST) | 8 of 10 (AST09, AST10 documented open) | None | None |
| OWASP MCP Top 10 | Full (MCP01–MCP10) | None | None |
| Output | |||
| SARIF v2.1.0 Output | Yes | No | No |
| HTML Report | Yes | Limited | No |
| JSON Output | Yes | Yes | Yes |
| Environment | |||
| Offline / Air-gapped Mode | Yes (--offline) | No | No |
| Policy Presets | default / strict / defence + JSON policy | No | No |
| Versioned Scoring Rubric | Yes (--rubric) | No | No |
| CI/CD Integration | Yes (exit codes + SARIF) | Limited | No |
| Pre-commit Hook | Yes | No | No |
| Risk Management | |||
| Accepted-Risk Suppressions | Yes (.sentinel-suppressions.json) | No | No |
| Counter-Factual Grading | Yes | No | No |
| Rug-Pull / Schema Mutation Detection | Yes (SS-022) | No | No |
| Confidence-Aware Triage | Yes (--triage) | No | No |
| Scan History & Diff | Yes (sentinel-scan diff) | No | No |
| Orchestrator-Agnostic Scope | Yes (.sentinel-scope.json) | No | No |
| Discovery | |||
| MCP Config Auto-Discovery | 10 platforms | 2 platforms | 1 platform |
| Agent Skill Auto-Discovery | 8 platforms + generic dirs | None | None |
| Attack Path Analysis | Yes (cross-server) | No | No |
| Transport | |||
| stdio (local) | Yes | Yes | Yes |
| HTTP/SSE | Yes | Yes | Limited |
| Streamable HTTP | Yes | No | No |
| WebSocket (ws/wss) | Yes | No | No |
| Licence & Cost | |||
| Open Source | Apache 2.0 | Partial | No |
| Free to Use | Yes | Free tier | Paid |
| Docker (Multi-arch) | Alpine, amd64/arm64 | Single arch | None |
| Script Analysis (.py, .sh, .ps1, .js, .ts and more) | Yes | No | No |
Information sourced from public documentation, GitHub repositories, and product pages. Signal Coding makes no guarantee of accuracy for third-party tools. Check each vendor's current documentation for the latest information.
Why organisations choose Signal Sentinel Scanner
Most comprehensive rule set
49 security rules (42 detection + 7 informational) across four scan surfaces – the broadest coverage of any open-source MCP scanner. Covers tool, prompt and resource poisoning, rug-pulls, supply chain attacks, SkillJacking, credential exposure, data exfiltration, fetch-to-exec pipelines, and more.
Triple OWASP mapping
Every finding maps to OWASP Agentic AI Top 10 (ASI), Agentic Skills Top 10 (AST), and MCP Top 10 simultaneously. Simplifies compliance reporting across all three frameworks.
Built for regulated environments
Offline mode (--offline) provides zero network egress for air-gapped, HMG, and Defence environments subject to JSP 440 / 656, and the defence policy preset implies it. No telemetry, no callbacks, no model dependency.
SARIF for enterprise toolchains
Native SARIF v2.1.0 output integrates directly with GitHub Code Scanning, Azure DevOps Advanced Security, Defender for Cloud, and any SARIF-compatible tool – no converter needed.
Audit-ready suppression workflow
Accept specific risks with documented justification, approver, expiry, and per-environment scoping. Counter-factual grading ensures suppressions cannot hide risk from leadership.
Truly free and open source
Apache 2.0 licence. No paid tier for core functionality. No registration. No telemetry. The source code is auditable and the binary is reproducible.
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Last updated: September 2026