CVE MCP Server

AI-powered security intelligence at your fingertips — 28 tools + a one-calltriage_cveorchestrator, 24 data sources, one protocol.[](https://mahipal.engineer/survey?utm_source=github_badge&amp;utm_medium=readme&amp;utm_campaign=gars2026)<<<[](https://python.org)<<<[](https://github.com/mukul975/cve-mcp-server/blob/HEAD/LICENSE)<<<[](https://modelcontextprotocol.io)<<<[](https://github.com/mukul975/cve-mcp-server)<<<

- 60 questions · Anonymous · Supervised by SRH Berlin
- You get50 Casky Tokensfor early access tocasky.ai
- Results published open access under CC-BY 4.0

- Architecture
- Tool catalog
- Installation
- API keys setup
- Configuration
- Quick start
- Usage examples
- Risk score explained
- Data sources
- Running tests
- Architecture deep dive
- Security and privacy
- Troubleshooting
- Roadmap and known limitations
- Contributing
- License

┌─────────────────────────────────────────────────────────────────────┐ │ Claude Desktop / Claude Code │ │ (MCP Client via stdio) │ └──────────────────────────────┬──────────────────────────────────────┘ │ Model Context Protocol (stdio) ▼ ┌─────────────────────────────────────────────────────────────────────┐ │ CVE MCP Server (Python) │ │ ┌─────────────┐ ┌──────────────┐ ┌───────────────┐ │ │ │ 27 MCP │ │ Composite │ │ SQLite Cache │ │ │ │ Tools │ │ Risk Engine │ │ + Audit Log │ │ │ └──────┬──────┘ └──────┬───────┘ └───────┬───────┘ │ │ │ │ │ │ │ ┌──────┴────────────────┴───────────────────┴──────┐ │ │ │ Async HTTP Client (httpx) │ │ │ │ Rate Limiter · Response Cache │ │ │ └──────────────────────┬───────────────────────────┘ │ └─────────────────────────┼───────────────────────────────────────────┘ │ HTTPS (outbound only) ┌───────────────┼───────────────────────────┐ ▼ ▼ ▼ ┌──────────────┐ ┌──────────────┐ ┌──────────────┐ │ VULNERABILITY│ │ NETWORK │ │ THREAT │ │ INTELLIGENCE │ │ INTELLIGENCE │ │ INTELLIGENCE │ ├──────────────┤ ├──────────────┤ ├──────────────┤ │ NVD API 2.0 │ │ AbuseIPDB │ │ VirusTotal │ │ EPSS / FIRST │ │ GreyNoise v3 │ │ MalwareBazaar│ │ CISA KEV │ │ Shodan │ │ ThreatFox │ │ OSV.dev │ │ CIRCL PDNS │ │ Ransomwhere │ │ GitHub GHSA │ │ │ │ AlienVault │ │ MITRE ATT&CK │ │ │ │ URLScan.io │ └──────────────┘ └──────────────┘ └──────────────┘

# 1. Clone the repository git clone https://github.com/mukul975/cve-mcp-server.git cd cve-mcp-server # 2. Create and activate a virtual environment python -m venv venv # macOS / Linux: source venv/bin/activate # Windows (PowerShell): .\venv\Scripts\Activate.ps1 # Windows (CMD): venv\Scripts\activate.bat # 3. Install dependencies pip install -e . # 4. Copy and configure environment variables cp .env.example .env # Edit .env with your API keys (see API Keys Setup section below) # 5. Verify the server starts python -m cve_mcp.server

git clone https://github.com/mukul975/cve-mcp-server.git cd cve-mcp-server uv venv source .venv/bin/activate # or .venv\Scripts\activate on Windows uv pip install -e . cp .env.example .env

# NVD API key — free at https://nvd.nist.gov/developers/request-an-api-key # Without key: 5 req/30s | With key: 50 req/30s NVD_API_KEY= # GitHub token — increases rate limit from 60/hr to 5000/hr (no scopes needed) GITHUB_TOKEN= # Threat intelligence keys (all optional — tools degrade gracefully without them) ABUSEIPDB_KEY= # https://www.abuseipdb.com/account/api VIRUSTOTAL_KEY= # https://www.virustotal.com/gui/join-us URLSCAN_KEY= # https://urlscan.io/user/signup SHODAN_KEY= # https://account.shodan.io/register # GreyNoise — uses /v3/ip/{ip} endpoint (NOT the deprecated /v3/community) GREYNOISE_API_KEY= # https://viz.greynoise.io/signup # CIRCL Passive DNS — requires partner registration CIRCL_PDNS_USER= CIRCL_PDNS_PASS= # Optional overrides CACHE_DB_PATH= # defaults to ~/.cve-mcp/cache.db AUDIT_LOG_PATH= # defaults to ~/.cve-mcp/audit.log REQUEST_TIMEOUT=30 # HTTP timeout in seconds MAX_RETRIES=3 # retries on transient errors

{ "mcpServers": { "cve-mcp": { "command": "python", "args": ["-m", "cve_mcp.server"], "cwd": "/absolute/path/to/cve-mcp-server", "env": { "NVD_API_KEY": "your-key-here", "GITHUB_TOKEN": "ghp_xxxxxxxxxxxxxxxxxxxx", "ABUSEIPDB_KEY": "your-abuseipdb-key", "GREYNOISE_API_KEY": "your-greynoise-key", "SHODAN_KEY": "your-shodan-key" } } } }

⚠️Important:Always useabsolute paths. Fully quit Claude Desktop (Cmd+Q / Alt+F4) after changing the config — reloading is not enough.

# Basic setup claude mcp add cve-mcp -- python -m cve_mcp.server # With environment variables (repeat -e for each key) claude mcp add cve-mcp -e NVD_API_KEY=your_key -e VULNCHECK_TOKEN=your_token -- python -m cve_mcp.server # Or just run from the project directory — python-dotenv auto-loads .env on startup # Verify it's connected claude mcp list

git clone https://github.com/mukul975/cve-mcp-server.git cd cve-mcp-server python -m venv venv && source venv/bin/activate pip install -e .

No.envfile needed. Add the server to Claude Desktop or Claude Code and try:

"What is CVE-2021-44228? Is it actively exploited?"

Claude will uselookup_cve(NVD),get_epss_score(EPSS), andcheck_kev(CISA KEV) — all free, no keys required.

"Scan these Python packages for vulnerabilities: requests 2.28.0, flask 2.2.0, django 3.2.0"

Step 3: Add your first key for 10× performance

echo 'NVD_API_KEY=your-key-here' > .env

Request a free NVD key atnvd.nist.gov— instant via email, increases rate limit from5 to 50 requests per 30 seconds.

→ lookup_cve("CVE-2021-44228") CVSS 3.1: 10.0 (CRITICAL) | AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H → get_epss_score("CVE-2021-44228") EPSS: 0.97531 (97.5%) | Percentile: 99.99% → check_kev("CVE-2021-44228") ✅ IN CISA KEV — Added 2021-12-10 | Known ransomware use: Yes → check_poc_exists("CVE-2021-44228") ✅ WEAPONIZED — 300+ public PoC repositories found → calculate_risk_score("CVE-2021-44228") Risk Score: 97/100 (CRITICAL) | Urgency: PATCH IMMEDIATELY

→ scan_dependencies(ecosystem="PyPI", packages={...}) Found 12 vulnerabilities across 4 packages

→ check_ip_reputation("185.220.101.34") AbuseIPDB Confidence: 100% | Reports: 4,832 | ISP: Tor Exit Node → check_ip_noise("185.220.101.34") GreyNoise: MALICIOUS | Tags: [Tor Exit Node, Web Scanner] CVEs targeted: CVE-2024-3400, CVE-2023-46805 → shodan_host_lookup("185.220.101.34") Open ports: 22, 80, 443, 9001 | OS: Linux

Claude's response:"185.220.101.34 is a known Tor exit noderated 100% malicious by AbuseIPDB with 4,832 abuse reports. GreyNoise confirms active scanning for CVE-2024-3400 (Palo Alto) and CVE-2023-46805 (Ivanti).Recommendation: Block at firewall."

Scenario 4: "Generate an executive security report"

You:Generate an executive security report for: CVE-2024-3400, CVE-2023-44487, CVE-2023-4966, CVE-2024-21887

→ compare_cves([...]) Compiles: NVD, EPSS, KEV, PoC availability, MITRE ATT&CK mapping Generates: Ranked risk table, remediation timeline, executive summary

Thecalculate_risk_scoretool produces acomposite risk score from 0 to 100by weighting four independent signals.

Risk Score = (CVSS × 0.20) + (EPSS × 0.35) + (KEV × 0.30) + (PoC × 0.15)

- KEV + active PoC→ ×1.15
- CVSS ≥ 9.0 + EPSS > 0.7→ ×1.10
- Published < 7 days ago→ ×1.05

The numeric scorer isscoring_version1.0(surfaced intriage_cve,calculate_risk_score, andhealth_check). The linear weighted sum above is the v1 default for thenumericscore, with one hard override:

- CISA KEV hard override:a KEV-listed CVE is confirmed exploited in the wild, the single strongest exploitation signal. Its label can never be lower thanCRITICALand its score is clamped to≥ 76, regardless of CVSS/EPSS. (A KEV CVE with a low CVSS and low EPSS still returns CRITICAL / 76.)
- CVSS is treated as aseveritysignal, not an exploitation-likelihood signal (per Allodi & Massacci 2014); EPSS and KEV carry the exploitation signal.
- An experimentalSSVC v2gated decision (CISA Deployer model →Act/Attend/Track*/Track) is available viatriage_cve(depth="deep")as a qualitative, explainable alternative to the 0–100 number.

EPSS gets the highest weight (35%)because it's the single best predictor of actual exploitation — far better than CVSS alone. A CVSS 10.0 with EPSS 0.01 is theoretically dangerous but practically unlikely.KEV at 30%is ground truth: confirmed exploitation, not a prediction.CVSS at 20%captures severity context for new CVEs with insufficient EPSS data.PoC at 15%reflects that public exploits dramatically accelerate real-world attacks.

- triage_cveorchestrator— one tool call that fans out NVD + EPSS + CISA KEV (+ public PoC discovery fordepth != "quick") concurrently, computes the composite risk score, and returns a clean report.depthisquick/standard(default) /deep;deepadditionally emits the SSVC v2 gated decision.
- New upstream sources— VulnCheck NVD++ (a transparent NVD fallback used automatically insidetriage_cvewhen NIST NVD is unreachable/throttled), CIRCL hashlookup, and the HIBP Pwned Passwords range API.
- KEV hard-override scoring+scoring_version— KEV-listed CVEs are always CRITICAL (score ≥ 76); the scoring version is reported intriage_cveandhealth_check.
- HTTP transport— setMCP_TRANSPORT=httpto serve streamable-HTTP onHOST:PORT(default0.0.0.0:8000, stateless) instead of stdio. Ships with aDockerfile.
- Resources & prompts— resourceskev://catalog,epss://scores/{cve_id}, andmanifest://tool-hash(SHA-256 over the registered tool surface); promptspatch_decision,compare_and_prioritize, anddependency_triage.
- Security posture— the server never registers a sampling handler / never issuessampling/createMessage(Unit 42 MCP-sampling attack vector); new outbound paths are scheme/host-allowlisted.

# Run the full test suite pytest tests/ -v # Run specific test files pytest tests/test_validators.py tests/test_risk_scorer.py -v # Run with coverage pytest tests/ -v --cov=src/cve_mcp --cov-report=term-missing

npx @modelcontextprotocol/inspector python -m cve_mcp.server

Opens athttp://localhost:6274— interactively test each tool, view input schemas, and inspect response formats.

- Unit tests:Risk score calculation, CVSS vector parsing, input validation
- Integration tests:Tool registration, parameter validation, error handling for missing keys
- Cache tests:SQLite cache writes, TTL expiration, cache hit/miss
- Security tests:Private IP blocking, XML bomb protection (defusedxml), input sanitization

src/cve_mcp/ ├── server.py # FastMCP server — all 27 @mcp.tool() definitions ├── config.py # Environment config and API base URLs ├── models.py # Pydantic models (CVERecord, KEVEntry, EPSSScore, ...) ├── audit.py # Rotating audit log (50MB, 5 backups) ├── api/ │ ├── nvd_client.py # NVD REST API v2.0 │ ├── osv_client.py # OSV.dev package vulnerability API │ ├── epss_client.py # FIRST EPSS API │ ├── kev_client.py # CISA KEV catalog │ ├── ip_intel.py # AbuseIPDB + GreyNoise │ ├── domain_intel.py # crt.sh + CIRCL passive DNS │ ├── shodan_client.py # Shodan host intelligence │ ├── hash_intel.py # MalwareBazaar + VirusTotal │ ├── url_safety.py # URLScan.io │ ├── malware_intel.py # ThreatFox IOC lookup │ ├── ransomware_intel.py# Ransomwhere Bitcoin address lookup │ ├── exploit_intel.py # GitHub PoC/exploit search │ ├── vendor_advisory.py # MSRC + Red Hat + Ubuntu advisories │ ├── attack_mapping.py # MITRE ATT&CK STIX mapping │ ├── cve_timeline.py # CVE event timeline builder │ ├── dependency_scan.py # OSV-based dependency scanning │ ├── poc_checker.py # GitHub + Exploit-DB + Nuclei PoC search │ ├── report_generator.py# Vuln report + CVE comparison matrix │ └── rate_limiter.py # Token bucket rate limiter for NVD ├── cache/ │ └── sqlite_cache.py # Async SQLite cache with per-key TTL └── utils/ ├── validators.py # CVE ID normalization, IP/hash validation └── risk_scorer.py # Composite risk score computation

Every tool invocation is logged to~/.cve-mcp/audit.log:

{ "timestamp": "2026-04-14T10:23:45.123Z", "tool": "lookup_cve", "parameters": {"cve_id": "CVE-2024-3400"}, "duration_ms": 342, "cache_hit": false, "status": "ok" }

API keys and response payloads arenever written to audit logs.

- Outbound HTTPS only— no inbound ports opened, no telemetry
- CVE IDs, IPs, hashes, domains, and package names are sent to respective APIs for lookup
- API responses are cached locally in SQLite — cached data stays on your machine

All network intelligence tools block private and reserved IP ranges before any external API call:

- 10.0.0.0/8,172.16.0.0/12,192.168.0.0/16(RFC 1918)
- 127.0.0.0/8(loopback),169.254.0.0/16(link-local)
- ::1,fc00::/7(IPv6 private)

- Keys loaded from environment variables only — never hardcoded
- .envis gitignored
- Keys never logged, cached, or included in audit entries

defusedxmlis used for all XML parsing to prevent XML bomb attacks (billion laughs, XXE injection).

# Ensure virtual environment is activated and package is installed pip install -e . python --version # must be 3.10+

Claude Desktop doesn't show the hammer icon (🔨)

- Check for JSON syntax errors (no trailing commas) in your config
- Useabsolute paths— relative paths silently fail
- Fully quit Claude Desktop (Cmd+Q / Alt+F4) and restart

# Add your free NVD API key to .env NVD_API_KEY=your-key-here # https://nvd.nist.gov/developers/request-an-api-key

The server queues excess requests automatically, but with a key you get 10× throughput.