v3.16.0 - MCP Scanner Hardening

v3.16.0 - MCP Scanner Hardening

9 new detection rules for comprehensive MCP manifest security scanning.

New Features

Schema-level injection detection:

• mcp.schema-description-injection (ERROR) - Detects injection language in property descriptions
• mcp.schema-suspicious-default (ERROR) - Flags suspicious default values with shell commands/URLs
• mcp.schema-open-additionalProperties (WARNING) - Flags additionalProperties:true with empty properties

Cross-tool manipulation detection:

• mcp.cross-tool-reference (ERROR) - Detects tool descriptions directing LLM to invoke other tools
• mcp.cross-tool-priority-override (ERROR) - Flags tools claiming execution priority

Statistical anomaly detection:

• mcp.description-length-anomaly (WARNING) - Z-score analysis to flag outlier descriptions

Suspicious URL detection:

• mcp.description-suspicious-url (WARNING) - Flags external URLs in descriptions
• mcp.description-tunneling-url (ERROR) - Detects ngrok, webhook.site, etc.

Nested base64 detection:

• nested-base64 (ERROR) - Detects double-encoded base64 obfuscation

Bug Fixes

• YAML rule paths filter support (respects paths.include/exclude)
• Fixed use-escapexml false positives on JS template literals
• Added .scannerrc.yaml for rule suppression
• CI fork permission handling

Test Coverage

• 17 new tests (100% pass rate)
• 14 new tests in scan-mcp.test.js
• 3 new tests in scan-prompt.test.js

Contributors

• @Har1sh-k - PR #20 (scanner hardening, path filter fix, CI improvements)

See CHANGELOG for full details.