NVD MCP Server — Azure Functions (Python)

A remote MCP (Model Context Protocol) server that exposes the NIST National Vulnerability Database (NVD) APIs as AI-callable tools. Built on Azure Functions with Python, deployed via azd.

The NVD API key is optional — the server works without one at a lower rate limit (5 req/30s unauthenticated vs 50 req/30s authenticated). Get a free key at nvd.nist.gov/developers/request-an-api-key.

Available MCP Tools

Tool	Description
`search_cves`	Search the CVE database by keyword, severity, CWE, CPE, date ranges, KEV membership, and more
`get_cve`	Retrieve full details for a specific CVE (CVSS scores, affected configurations, references)
`get_cve_history`	Get the NVD change history for CVE records — shows when scores, status, or analysis were updated
`search_cves_by_cpe`	Find all CVEs affecting a specific product by its CPE 2.3 name
`get_recent_cves`	Get CVEs published in the last N days, optionally filtered by severity or KEV status
`search_cpes`	Search for CPE product entries by name — use this to find the exact CPE URI for other tools
`get_kev`	Fetch the CISA Known Exploited Vulnerabilities catalog live, with keyword/date/ransomware filtering

Quickstart — GitHub Codespaces (zero local install)

The repo includes a pre-configured dev container that has all tools installed automatically (Python, azd, az, func, Node, Azurite, MCP Inspector).

Or open locally in VS Code:

Install the Dev Containers extension
Clone the repo and open it in VS Code
When prompted, click Reopen in Container

Everything in the Run locally and Deploy to Azure sections will work inside the container without installing anything on your machine.

Note (Codespaces): Azurite starts automatically in the background every time the container starts. You can proceed directly to step 2 of Run locally.

Prerequisites

Python 3.12 recommended (matches deployed Functions runtime), 3.11+ supported for local development
Azure Functions Core Tools >= 4.0.7030
Azure Developer CLI (azd)
Azure CLI (az)
Node.js (for Azurite local storage emulator)
VS Code + Azure Functions extension (optional)

Installing prerequisites on macOS

The easiest way is via Homebrew:

# Install Homebrew if you don't have it
/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"

# Install tools
brew install azure-developer-cli
brew install azure-cli
brew tap azure/functions
brew install azure-functions-core-tools@4
brew install node

Installing prerequisites on Windows

winget install Microsoft.Azd
winget install Microsoft.AzureCLI
winget install OpenJS.NodeJS.LTS
npm install -g azure-functions-core-tools@4 --unsafe-perm true

Run locally

1. Start the storage emulator

Azurite emulates Azure Storage locally and is required by the Functions host.

npx azurite --location ~/.azurite --silent

Leave this running in a separate terminal tab.

Codespaces: Azurite is already running — skip this step.

2. Create a virtual environment and install dependencies

The Python worker resolves packages from a .venv folder inside src/.

cd src
python -m venv .venv

Install dependencies:

# macOS / Linux
.venv/bin/pip install -r requirements.txt

# Windows (PowerShell)
.venv\Scripts\pip install -r requirements.txt

Verify the install succeeded:

# macOS / Linux
.venv/bin/python -c "import azure.functions; print('OK')"

# Windows
.venv\Scripts\python -c "import azure.functions; print('OK')"

Expected output: OK

3. Configure local settings

# macOS / Linux
cp src/local.settings.json.example src/local.settings.json

# Windows PowerShell
Copy-Item src\local.settings.json.example src\local.settings.json

Edit src/local.settings.json and optionally fill in your NVD API key:

{
  "IsEncrypted": false,
  "Values": {
    "FUNCTIONS_WORKER_RUNTIME": "python",
    "AzureWebJobsStorage": "UseDevelopmentStorage=true",
    "PYTHON_ISOLATE_WORKER_DEPENDENCIES": "1",
    "NVD_API_KEY": "<your-key-or-leave-empty>"
  }
}

Note: local.settings.json is gitignored and will never be committed.

4. Start the Functions host

cd src
func start

Wait until you see output similar to:

Azure Functions Core Tools
...
Functions:
        search_cves: [POST,GET] http://localhost:7071/runtime/webhooks/mcp
        get_cve: [POST,GET] http://localhost:7071/runtime/webhooks/mcp
        ...
Host lock lease acquired by instance ID ...

The MCP server is now available at http://localhost:7071/runtime/webhooks/mcp.

Troubleshooting: If func start fails with a storage error, make sure Azurite is running (step 1). If it fails with an import error, ensure you installed dependencies into src/.venv (step 2).

Connect from a client

VS Code — GitHub Copilot agent mode

Open .vscode/mcp.json. Click Start above the local-mcp-function server entry. Then ask Copilot:

Search for critical CVEs related to log4j

Get the full details for CVE-2021-44228

What CVEs have been added to the KEV catalog in the last 30 days?

MCP Inspector

npx @modelcontextprotocol/inspector

Set transport to Streamable HTTP, URL to http://localhost:7071/runtime/webhooks/mcp, and click Connect.

Deploy to Azure

1. Log in to Azure

azd auth login

Also log in with the Azure CLI (required for some post-deployment steps):

az login

2. Create an azd environment

azd env new <your-environment-name>

3. Set required environment variables

# Required: choose a supported region (see infra/main.bicep for the full allowed list)
azd env set AZURE_LOCATION <region>   # e.g. uksouth, swedencentral, eastus

# Required: set to true to deploy with VNet + private endpoints, false for public access
azd env set VNET_ENABLED false

Choose exactly one authentication mode before azd up:

Mode	Env vars to set	Behavior
Key-based (default)	None	MCP webhook uses Functions system key auth
Entra (EasyAuth)	`azd env set ENTRA_AUTH_ENABLED true`	Preprovision hook creates/reuses app registration and sets `ENTRA_APP_CLIENT_ID`; webhook auth is delegated to EasyAuth
Unauthenticated (dev only)	`azd env set MCP_UNAUTHENTICATED_ACCESS true`	MCP webhook is publicly accessible with no auth

Do not set both ENTRA_AUTH_ENABLED=true and MCP_UNAUTHENTICATED_ACCESS=true. If both are set, the preprovision hook prioritizes unauthenticated access.

Quick verification:

azd env get-values

Multiple subscriptions? If your account has more than one subscription, also run:
azd env set AZURE_SUBSCRIPTION_ID <your-subscription-id>

4. (Optional) Set your NVD API key

azd env set NVD_API_KEY <your-key>

If you skip this step, the server deploys and works unauthenticated against NVD (lower NVD rate limits). You can add the key later.

5. Deploy

azd up

This provisions a resource group containing:

Azure Functions app (Flex Consumption plan)
Azure Key Vault (stores the NVD API key if provided)
Azure Storage account
Application Insights + Log Analytics workspace
User-assigned managed identity

If VNET_ENABLED=true, Function App public network access is disabled and the MCP endpoint is only reachable from the private network.

When deployment completes, azd up prints the MCP endpoint URL:

Outputs:
  MCP_ENDPOINT: https://<funcappname>.azurewebsites.net/runtime/webhooks/mcp

6. Connect to the remote MCP server

Your endpoint format:

https://<funcappname>.azurewebsites.net/runtime/webhooks/mcp

Key-based mode (default)

Get the system key:

az functionapp keys list \
  --name <function-app-name> \
  --resource-group <resource-group> \
  --query "systemKeys.mcp_extension" -o tsv

In VS Code, click Start on remote-mcp-function in .vscode/mcp.json and provide function app name + system key.

Entra mode (`ENTRA_AUTH_ENABLED=true`)

Use a bearer token for scope api://<ENTRA_APP_CLIENT_ID>/user_impersonation instead of x-functions-key.

az account get-access-token \
  --scope "api://<ENTRA_APP_CLIENT_ID>/user_impersonation" \
  --query accessToken -o tsv

Configure your MCP client to send:

Authorization: Bearer <access-token>

Unauthenticated mode (`MCP_UNAUTHENTICATED_ACCESS=true`)

No auth header is required. Use only for isolated development scenarios.

Update the NVD API key after deployment

az keyvault secret set \
  --vault-name <keyvault-name> \
  --name NVD-API-KEY \
  --value <new-key>

The Function App resolves the Key Vault reference automatically on next invocation (cached up to ~24h; restart the app for immediate effect).

This command requires RBAC permission to write Key Vault secrets (for example, Key Vault Secrets Officer). The current template defaults to least privilege and does not auto-assign this role to the deploying user.

Secrets management

Context	How the key is stored
Local	`src/local.settings.json` (gitignored)
Azure	Azure Key Vault secret; Function App reads it at runtime via a Key Vault reference using a user-assigned managed identity — the raw key never appears in app configuration
Deploy	`azd env set NVD_API_KEY <key>` writes to `.azure/*/env.json` (gitignored by root `.gitignore`, but still plaintext on your machine)

Helpful commands

# Redeploy code without reprovisioning infrastructure
azd deploy

# View live function logs
az webapp log tail --name <funcappname> --resource-group <rg>

# Tear down all Azure resources
azd down

MCP Tools Reference

Each tool below documents its parameters and gives example prompts. When used via an AI assistant (e.g. GitHub Copilot), the AI selects the appropriate tool and fills in the parameters based on the conversation.

`search_cves`

Search the NVD CVE database with flexible filters. Returns matching vulnerabilities with CVSS scores, descriptions, references, and metadata.

Parameters

Parameter	Type	Required	Description
`keyword`	string	No	Keywords to search within CVE descriptions and titles (e.g. `log4j`, `remote code execution`)
`cve_id`	string	No	A specific CVE identifier (e.g. `CVE-2021-44228`). When provided, other filters are ignored
`cpe_name`	string	No	CPE 2.3 name to filter CVEs for a specific product (e.g. `cpe:2.3:a:apache:log4j:*`)
`cvss_v3_severity`	string	No	Filter by CVSS v3 severity: `LOW`, `MEDIUM`, `HIGH`, or `CRITICAL`
`cwe_id`	string	No	Filter by CWE identifier (e.g. `CWE-79` for XSS)
`pub_start_date`	string	No	Publication start date in ISO 8601 format (e.g. `2024-01-01T00:00:00.000`). Max range: 120 days
`pub_end_date`	string	No	Publication end date in ISO 8601 format. Max range: 120 days
`last_mod_start_date`	string	No	Last-modified start date in ISO 8601 format. Max range: 120 days
`last_mod_end_date`	string	No	Last-modified end date in ISO 8601 format. Max range: 120 days
`has_kev`	boolean	No	When `true`, return only CVEs in the CISA Known Exploited Vulnerabilities catalog
`results_per_page`	integer	No	Results per page (1–2000). Default: `20`
`start_index`	integer	No	Zero-based index for pagination. Default: `0`

Example prompts

Search for critical CVEs related to log4j
Find all XSS vulnerabilities (CWE-79) published this year
Show me HIGH severity CVEs that are in the KEV catalog
Search for CVEs affecting Apache HTTP Server published between 2024-01-01 and 2024-03-31

`get_cve`

Retrieve the complete record for a single CVE by its identifier. Returns CVSS v2 and v3 scores, weakness data (CWE), affected product configurations (CPE), reference links, and current status.

Parameters

Parameter	Type	Required	Description
`cve_id`	string	Yes	The CVE identifier (e.g. `CVE-2021-44228`)

Example prompts

Get the full details for CVE-2021-44228
What is the CVSS score and description for CVE-2023-44487?
Show me all affected products for CVE-2024-3094

`get_cve_history`

Retrieve the NVD change history for CVE records. Useful for auditing when a vulnerability was initially analysed, when scores were revised, or when the status changed to Rejected.

Parameters

Parameter	Type	Required	Description
`cve_id`	string	No	Retrieve history for a specific CVE. Leave empty to query by date range
`change_start_date`	string	No	Start of the change-event date range in ISO 8601 format. Max range: 120 days
`change_end_date`	string	No	End of the change-event date range in ISO 8601 format. Max range: 120 days
`event_name`	string	No	Filter by event type: `Initial Analysis`, `Reanalysis`, `CVE Modified`, `CVE Rejected`, `CVE Translated`
`results_per_page`	integer	No	Results per page (1–5000). Default: `20`
`start_index`	integer	No	Zero-based index for pagination. Default: `0`

Note: You must supply either cve_id or a date range (change_start_date + change_end_date). Supplying neither returns an API error.

Example prompts

Show the change history for CVE-2021-44228
What CVE records were modified in the NVD last week?
List all CVEs that were rejected between 2024-01-01 and 2024-03-31
When was CVE-2023-44487 first analysed?

`search_cves_by_cpe`

Find all CVEs that affect a specific product using its CPE 2.3 name. Use search_cpes first to discover the exact CPE URI.

Parameters

Parameter	Type	Required	Description
`cpe_name`	string	Yes	CPE 2.3 name (e.g. `cpe:2.3:a:apache:log4j:2.14.1:::::::*`)
`results_per_page`	integer	No	Results per page (1–2000). Default: `20`
`start_index`	integer	No	Zero-based index for pagination. Default: `0`

Example prompts

Find all CVEs for Apache Log4j 2.14.1
What vulnerabilities affect OpenSSL 3.0?

`get_recent_cves`

Get CVEs published in the last N days. A quick way to see what new vulnerabilities have been disclosed, optionally filtered by severity or KEV status.

Parameters

Parameter	Type	Required	Description
`days`	integer	No	How many days back to look (1–120). Default: `7`
`cvss_v3_severity`	string	No	Filter by CVSS v3 severity: `LOW`, `MEDIUM`, `HIGH`, or `CRITICAL`
`has_kev`	boolean	No	When `true`, return only CVEs in the CISA KEV catalog
`results_per_page`	integer	No	Results per page (1–2000). Default: `20`
`start_index`	integer	No	Zero-based index for pagination. Default: `0`

Example prompts

What critical CVEs were published in the last 7 days?
Show me new HIGH or CRITICAL vulnerabilities from the past 30 days
What recently published CVEs are already in the KEV catalog?
Give me a summary of this week's new vulnerabilities

`search_cpes`

Search the NVD CPE (Common Platform Enumeration) dictionary for product entries. Use this to find the exact CPE 2.3 URI needed by search_cves_by_cpe or the cpe_name filter in search_cves.

Parameters

Parameter	Type	Required	Description
`keyword`	string	No	Product name or vendor keyword (e.g. `apache tomcat`, `openssl`)
`cpe_match_string`	string	No	Partial CPE 2.3 string to match against (e.g. `cpe:2.3:a:microsoft`)
`results_per_page`	integer	No	Results per page (1–10000). Default: `20`
`start_index`	integer	No	Zero-based index for pagination. Default: `0`

Example prompts

Find the CPE name for Apache Tomcat 10
What is the exact CPE identifier for OpenSSL 3.1.0?
Search for all Microsoft products in the CPE dictionary

`get_kev`

Fetch the CISA Known Exploited Vulnerabilities (KEV) catalog live. The KEV catalog lists vulnerabilities that are known to be actively exploited in the wild and are subject to CISA binding operational directive BOD 22-01.

Parameters

Parameter	Type	Required	Description
`keyword`	string	No	Filter by vendor, product, or vulnerability name (case-insensitive)
`since`	string	No	Only return entries added to KEV on or after this date (`YYYY-MM-DD`)
`ransomware_only`	boolean	No	When `true`, return only entries with a known ransomware campaign association
`results_per_page`	integer	No	Maximum entries to return (1–2000). Default: `10`

Example prompts

What are the most recently added entries to the CISA KEV catalog?
Show me KEV entries added since 2024-01-01
Which KEV vulnerabilities are associated with ransomware campaigns?
Are there any Citrix products in the KEV catalog?

Source code

File	Purpose
src/function_app.py	MCP tool definitions (`search_cves`, `get_cve`, `get_cve_history`, `search_cves_by_cpe`, `get_recent_cves`, `search_cpes`, `get_kev`)
src/nvd_service.py	NVD REST API client and CISA KEV catalog fetcher
infra/main.bicep	Azure infrastructure (Functions, Key Vault, Storage, Monitoring)
infra/app/keyvault.bicep	Key Vault resource and RBAC role assignments

NVD API reference

CVE API — GET /cves/2.0
CVE History API — GET /cvehistory/2.0
CPE API — GET /cpes/2.0
Request an API key
CISA KEV Catalog — live JSON feed

Troubleshooting

func start fails with "Microsoft.Azure.Storage.Common" or storage-related errors

Azurite is not running. Start it in a separate terminal:

npx azurite --location ~/.azurite --silent

func start fails with "ModuleNotFoundError: No module named 'azure.functions'"

Dependencies were not installed into src/.venv. Run:

cd src
python -m venv .venv
.venv/bin/pip install -r requirements.txt   # macOS/Linux
# or
.venv\Scripts\pip install -r requirements.txt   # Windows

NVD API returns 403 or rate-limit errors

Without an API key the NVD API allows 5 requests per 30-second window. Add your key to src/local.settings.json (local) or run azd env set NVD_API_KEY <key> before deploying.

azd up fails with "VNET_ENABLED is not set"

This variable is required. Set it before deploying:

azd env set VNET_ENABLED false   # public access
# or
azd env set VNET_ENABLED true    # private/VNet-only access

Can't update the NVD API key in Key Vault after deployment

By default, the template does not grant the deploying user the Key Vault Secrets Officer role (least privilege). To enable key updates, assign the role manually:

KV=$(az keyvault list --resource-group <rg> --query "[0].name" -o tsv)
az role assignment create \
  --role "Key Vault Secrets Officer" \
  --assignee <your-user-object-id> \
  --scope $(az keyvault show --name $KV --query id -o tsv)

Then set the secret:

az keyvault secret set --vault-name $KV --name NVD-API-KEY --value <new-key>

MCP client shows "connection refused" for local server

Ensure func start is running and listening on port 7071. Check the terminal where you ran func start for errors.

Devcontainer / Codespace: Azurite not running after container restart

Azurite is configured to start automatically via postStartCommand. If it is not running, start it manually:

nohup npx azurite --location ~/.azurite --silent > ~/.azurite/azurite.log 2>&1 &

Name		Name	Last commit message	Last commit date
Latest commit History 13 Commits
.devcontainer		.devcontainer
.github		.github
.vscode		.vscode
infra		infra
scripts		scripts
src		src
tests		tests
.gitignore		.gitignore
LICENSE.md		LICENSE.md
README.md		README.md
azure.yaml		azure.yaml
pyproject.toml		pyproject.toml
requirements-dev.txt		requirements-dev.txt

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NVD MCP Server — Azure Functions (Python)

Available MCP Tools

Quickstart — GitHub Codespaces (zero local install)

Prerequisites

Installing prerequisites on macOS

Installing prerequisites on Windows

Run locally

1. Start the storage emulator

2. Create a virtual environment and install dependencies

3. Configure local settings

4. Start the Functions host

Connect from a client

VS Code — GitHub Copilot agent mode

MCP Inspector

Deploy to Azure

1. Log in to Azure

2. Create an azd environment

3. Set required environment variables

4. (Optional) Set your NVD API key

5. Deploy

6. Connect to the remote MCP server

Key-based mode (default)

Entra mode (ENTRA_AUTH_ENABLED=true)

Unauthenticated mode (MCP_UNAUTHENTICATED_ACCESS=true)

Update the NVD API key after deployment

Secrets management

Helpful commands

MCP Tools Reference

search_cves

get_cve

get_cve_history

search_cves_by_cpe

get_recent_cves

search_cpes

get_kev

Source code

NVD API reference

Troubleshooting

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Entra mode (`ENTRA_AUTH_ENABLED=true`)

Unauthenticated mode (`MCP_UNAUTHENTICATED_ACCESS=true`)

`search_cves`

`get_cve`

`get_cve_history`

`search_cves_by_cpe`

`get_recent_cves`

`search_cpes`

`get_kev`

Packages