patch-tuesday-mcp 0.4.0

MCP server for Microsoft Patch Tuesday security updates (MSRC Security Update Guide)

Disclaimer: This is an independent, self-built project and is not an official Microsoft tool or service.

Patch Tuesday MCP Server

mcp-name: io.github.jonnybottles/patch-tuesday

Ask your AI assistant about Microsoft security updates. This Python-based MCP (Model Context Protocol) server connects AI assistants like Claude, Copilot, and ChatGPT to the MSRC Security Update Guide — the authoritative source for every CVE Microsoft patches — enabling natural-language queries over Patch Tuesday releases: CVEs, KB articles, severity ratings, CVSS scores, affected products, and exploited-in-the-wild status.

What It Does

Patch Tuesday MCP Server bridges Microsoft's official CVRF security update API and your AI assistant, allowing you to:

• Get the monthly rollup - "What did this month's Patch Tuesday fix?"
• Find what's actively exploited - "Which vulnerabilities are being exploited in the wild?"
• Look up any CVE - "Tell me about CVE-2026-41108" (KBs, affected products, CVSS, description)
• Map KBs to CVEs - "Which vulnerabilities does KB5094123 fix?"
• Filter by product - "What Critical CVEs affect Windows Server 2022 this month?"
• Track zero-days - "Were any publicly disclosed vulnerabilities patched in April?"
• See what's confirmed exploited - "Which of this month's CVEs are on the CISA KEV list?" — with federal remediation due dates
• Rank by exploitation probability - "Show me CVEs with EPSS above 50%" — daily FIRST.org exploit prediction scores
• Find zero-click, internet-reachable criticals - "Which Critical CVEs are network-reachable with no privileges and no user interaction?" — filter on the parsed CVSS attack vector, privileges, and user-interaction fields
• Jump straight to authoritative sources - every CVE detail carries ready-to-open MSRC, NVD, EPSS, and (when listed) CISA KEV reference links
• Avoid stale patches - "Is KB5087538 superseded by anything newer?" — walks Microsoft's supersedence links
• Get mitigations when there's no patch yet - "Are there mitigations or workarounds for CVE-2026-47291?" — surfaces Microsoft's mitigation, workaround, and will-not-fix guidance
• Spot trends over time - "How many HTTP.sys CVEs shipped over the last 6 months?" (months_back=6, or start_month/end_month) — aggregates matches across released months with per-month counts
• Export a triage briefing - "Give me this month's Critical CVEs as a Markdown report" or "…as CSV" — a prioritized executive summary and table, or a spreadsheet-ready export (format="markdown" / format="csv")
• Force-refresh & check data freshness - "Re-pull this month's data fresh" (force_refresh=True) bypasses the in-process caches; include_freshness=True reports the cache age/TTL of the MSRC document and EPSS/KEV enrichment
• Prioritize patching - Results are sorted most-urgent-first: KEV/exploited, then EPSS, then severity, then CVSS

Perfect for security analysts, sysadmins, and IT professionals who triage Microsoft security updates every month — without clicking through the Security Update Guide portal.

Data comes from the official, public MSRC CVRF v3 API. No authentication or API key required.

Why This Server?

This is the only MCP server that models the Patch Tuesday release itself. Plenty of MCP servers can look up a CVE — general-purpose vulnerability aggregators fan a known CVE ID out across NVD, OSV, and threat-intel feeds. They answer "tell me about CVE-X". But they have no concept of a monthly Microsoft release, a KB article, or a product family — so they structurally cannot answer the questions a Microsoft shop actually asks on the second Tuesday of every month:

The question you actually have	Generic CVE lookup servers	patch-tuesday-mcp
"Summarize this month's Patch Tuesday"	❌ no concept of a release	✅ rollup + stats in one call
"What Critical CVEs affect Windows Server 2022 this month?"	❌ can't filter by Microsoft product	✅ product & family filtering
"Which vulnerabilities does KB5094123 fix?"	❌ no KB awareness	✅ KB ↔ CVE mapping
"What's being exploited in the wild right now?"	⚠️ per-CVE only, if you already know the CVE	✅ filter the whole month
"What do I patch first?"	❌	✅ urgency-sorted: exploited/KEV → EPSS → severity → CVSS
"Which criticals are zero-click and internet-reachable?"	⚠️ per-CVE CVSS only	✅ filter the month by parsed CVSS attack vector / privileges / user interaction
"Tell me about CVE-X"	✅ (often with more ecosystem data)	✅ MSRC detail: KBs, builds, supersedence, parsed CVSS, MSRC/NVD/EPSS/KEV links

Under the hood, the difference is the data source: this server parses the full MSRC CVRF monthly documents — the ProductTree, per-product severity threats, exploitability assessments, and KB remediation chains that per-CVE APIs never expose. That's what makes release-centric questions possible.

Other things it deliberately gets right:

• Zero API keys, zero accounts — the MSRC API is public; setup is one uvx command
• One tool, not thirty — a single consolidated msrc_search keeps your AI client's context lean and tool selection reliable
• Built for the monthly workflow — triage a release, brief your team, prioritize patching, then get on with your life

Try It Instantly — Hosted Endpoint (No Install)

A free remote instance is available at:

https://patch-tuesday-mcp.happyrock-b60185ec.eastus.azurecontainerapps.io/mcp

No account or API key needed. The endpoint serves the same public data as a local install — for heavy use or guaranteed availability, run it locally (below) or self-host your own. Only minimal, anonymized usage data is recorded — see Telemetry & Privacy.

Requirements

General

• Python 3.11+
• An MCP-compatible client (Claude Desktop, Cursor, Claude Code, GitHub Copilot CLI, etc.)

Using uvx (Recommended)

If you are installing or running the server via uvx, you must have uv installed first.

• uv (includes uvx): https://github.com/astral-sh/uv

Install uv:

# macOS / Linux
curl -LsSf https://astral.sh/uv/install.sh | sh

# Windows (PowerShell)
irm https://astral.sh/uv/install.ps1 | iex

uvx allows you to run the MCP server without installing the package globally.

Using pip (Alternative)

pip install patch-tuesday-mcp

Installation

Install from PyPI

uvx patch-tuesday-mcp

Or install with pip:

pip install patch-tuesday-mcp

Upgrade to Latest Version

uvx patch-tuesday-mcp@latest

Or with pip:

pip install --upgrade patch-tuesday-mcp

Quick Setup

One-click setup: Click the VS Code badge for automatic configuration (requires uv installed) Manual setup: See instructions below for VS Code, Cursor, Claude Code, Copilot CLI, or Claude Desktop

Features

• msrc_search – Search and filter Microsoft security updates by keyword, CVE, KB number, month, product, severity, CVSS score, exploited-in-the-wild status, or public disclosure. When no month is given, results default to the most recent release whose Patch Tuesday has already occurred — the upcoming month's pre-release document (early Chromium/out-of-band entries only) is skipped by default and available explicitly via month=. Results are enriched with EPSS scores (FIRST.org 30-day exploitation probability, min_epss=0.5 filter) and CISA KEV catalog status with federal remediation due dates (kev=True filter) — both public, keyless sources. Filter by the parsed CVSS v3.x exposure fields — attack_vector (N/A/L/P), privileges_required (N/L/H), user_interaction (N/R), and scope (U/C) — to isolate, for example, network-reachable zero-click criticals; matching results surface a structured cvss object broken out from the raw vector string. Every CVE detail also includes a references block of ready-to-open links (MSRC update guide, NVD, EPSS API, and the CISA KEV catalog when the CVE is listed). Add include_chain=True to a KB lookup to walk Microsoft-stated supersedence chains (which KBs it replaces, newest → oldest). Add include_guidance=True to a CVE lookup to surface Microsoft-provided mitigations, workarounds, and will-not-fix advisories alongside the vendor-fix KBs. Pass format="markdown" or format="csv" to a monthly/filtered search to get an additive triage briefing — a prioritized executive summary and table (Markdown) or a spreadsheet-ready export with stable columns (CSV) — rendered from the same urgency ranking; the JSON vulnerabilities list is always included. Use force_refresh=True to bypass the in-process caches and re-fetch the MSRC document and EPSS/KEV enrichment for the request, and include_freshness=True to add a freshness block reporting the cache age and TTL of the MSRC document and enrichment data. Search a historical range instead of a single month with months_back=N (the N most recent released months) or start_month/end_month — the response aggregates matching CVEs across the range and adds per-month trend counts; ranges are capped at 12 months and reuse the existing cache/concurrency controls. Set include_stats=True for aggregate counts (by severity, impact, product family, exploited, KEV). Use limit=0 with include_stats=True for a stats-only month overview.

Prompt Examples

Once connected to an MCP client, you can ask questions like:

1. Monthly overview: "Summarize this month's Patch Tuesday"
2. Exploited vulnerabilities: "Which Microsoft vulnerabilities are being actively exploited?"
3. CVE lookup: "What is CVE-2026-41108 and which KB fixes it?"
4. KB lookup: "What does KB5094123 patch?"
5. Product filter: "Show me Critical vulnerabilities affecting Exchange Server this month"
6. Patch prioritization: "What should I patch first from the June 2026 updates?"
7. CISA KEV: "Which of this month's CVEs are on the CISA KEV list?"
8. EPSS: "Show me CVEs with EPSS above 50%"
9. Exposure filtering: "Which Critical CVEs are network-reachable with no privileges and no user interaction?"
10. Reference links: "Give me the MSRC, NVD, and EPSS links for CVE-2026-41108"
11. Mitigations & workarounds: "Are there any mitigations or workarounds for CVE-2026-41108?"
12. Triage report: "Give me this month's Critical CVEs as a Markdown briefing" (or "…export them as CSV")
13. Fresh data on demand: "Re-pull this month's updates fresh and tell me how current the data is" (force_refresh=True, include_freshness=True)
14. Historical trends: "How many HTTP.sys RCE CVEs shipped over the last 6 months?" (query="HTTP.sys", months_back=6)
15. Supersedence: "Is KB5087538 superseded by anything newer?"

Usage

Run the MCP Server

uvx patch-tuesday-mcp

Or if installed with pip:

patch-tuesday-mcp

Connect from VS Code

Option 1: One-Click Install (Recommended)

Click the Set up in VS Code badge at the top of this README for automatic configuration (requires uv installed).

Option 2: Manual Configuration

VS Code stores MCP servers in a dedicated mcp.json file — not settings.json. Open the Command Palette (Ctrl+Shift+P on Windows/Linux, Cmd+Shift+P on macOS) and run one of:

• MCP: Open User Configuration — edits your user-level mcp.json (available in every workspace)
• MCP: Open Workspace Folder Configuration — edits a project-local .vscode/mcp.json

Then add the server. Note that VS Code uses a top-level "servers" key (unlike the "mcpServers" key used by the other clients below):

{
  "servers": {
    "patch-tuesday": {
      "type": "stdio",
      "command": "uvx",
      "args": ["patch-tuesday-mcp"]
    }
  }
}

Connect from Claude Desktop

Add to your Claude Desktop MCP config:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json

Using uvx (recommended)

{
  "mcpServers": {
    "patch-tuesday": {
      "command": "uvx",
      "args": ["patch-tuesday-mcp"]
    }
  }
}

Using installed package

{
  "mcpServers": {
    "patch-tuesday": {
      "command": "patch-tuesday-mcp"
    }
  }
}

Connect from Cursor

Option 1: One-Click Install (Recommended)

cursor://anysphere.cursor-deeplink/mcp/install?name=patch-tuesday-mcp&config=eyJjb21tYW5kIjogInV2eCIsICJhcmdzIjogWyJwYXRjaC10dWVzZGF5LW1jcCJdfQ==

Option 2: Manual Configuration

Add to your Cursor MCP config (~/.cursor/mcp.json):

{
  "mcpServers": {
    "patch-tuesday": {
      "command": "uvx",
      "args": ["patch-tuesday-mcp"]
    }
  }
}

Connect from Claude Code

claude mcp add --transport stdio patch-tuesday -- uvx patch-tuesday-mcp

Connect from GitHub Copilot CLI

Add to ~/.copilot/mcp-config.json:

{
  "mcpServers": {
    "patch-tuesday": {
      "type": "stdio",
      "command": "uvx",
      "args": ["patch-tuesday-mcp"]
    }
  }
}

Self-Hosting as a Remote MCP Server

The server also supports the HTTP transport for remote/shared deployments:

MCP_TRANSPORT=http MCP_PORT=8000 patch-tuesday-mcp
# MCP endpoint: http://localhost:8000/mcp

Or with Docker:

docker build -t patch-tuesday-mcp .
docker run -p 8000:8000 patch-tuesday-mcp

HTTP-mode environment variables:

Variable	Default	Description
MCP_TRANSPORT	stdio	Set to http for remote serving
MCP_HOST / MCP_PORT	0.0.0.0 / 8000	Bind address
RATE_LIMIT_RPM	60	Per-IP requests/minute (0 disables)
MCP_MAX_BODY_BYTES	262144	Max request body size, returns 413 above it (0 disables)
MCP_CORS_ORIGINS	* (all)	Comma-separated allowlist of browser origins. Set an explicit list for public deployments (e.g. https://app.example.com)
MCP_TRUST_X_FORWARDED_FOR	true	Whether to derive the client IP for rate limiting from the X-Forwarded-For header. Set to false when the server is directly exposed (no reverse proxy), so a spoofed header can't evade or poison the limiter
MCP_TRUSTED_PROXIES	unset	Comma-separated proxy IPs. When set, X-Forwarded-For is only honored if the request arrives via one of these proxies, and the client is resolved as the right-most hop that is not itself a trusted proxy (unwinds chained proxies)
APPLICATIONINSIGHTS_CONNECTION_STRING	unset	Opt-in usage telemetry (requires pip install patch-tuesday-mcp[telemetry])

HTTP mode also serves GET /health (liveness endpoint, exempt from rate limiting) and runs stateless, so it can scale to multiple replicas behind a load balancer without session affinity.

Hardening a public HTTP deployment

The HTTP transport is unauthenticated — msrc_search only reads public vulnerability data, but an open endpoint is still abusable. Before exposing it to the internet:

• Put it behind an authenticated front door. Terminate TLS and require auth at a reverse proxy / API gateway (e.g. Azure API Management, an OAuth2/OIDC proxy such as oauth2-proxy, Cloudflare Access, or your ingress controller's auth). This server intentionally ships no built-in auth so you can layer your organization's standard access control in front of it.
• Restrict CORS. Set MCP_CORS_ORIGINS to the exact origins of your MCP clients instead of the permissive * default.
• Set the proxy trust correctly. When behind a reverse proxy, leave MCP_TRUST_X_FORWARDED_FOR=true and set MCP_TRUSTED_PROXIES to your proxy/ingress IP(s) so per-IP rate limiting keys on the real client. When the container is reachable directly (no proxy), set MCP_TRUST_X_FORWARDED_FOR=false so clients cannot forge the header.
• Keep the defaults on. Leave RATE_LIMIT_RPM and MCP_MAX_BODY_BYTES at their defaults (or tighten them) — they are your first line of defense against floods and oversized payloads.

Local stdio usage is unaffected by all of the above; none of this middleware runs for the default transport.

The container runs on any host that can serve HTTP — Azure Container Apps, Cloud Run, Fly.io, or a plain VM.

Telemetry & Privacy

• Local stdio (the default): no telemetry, ever — there is no code path that sends anything.
• The hosted endpoint records minimal usage data to Azure Application Insights (90-day retention): a daily-salted hash of the client IP (raw IPs are never stored; they are only held briefly in memory for abuse protection), request path and timestamp, which tool parameters were used (parameter names only — never your query text or CVE/KB values; only the low-cardinality month and severity values are kept), result counts, latency, and error categories. No cookies, no accounts, no request/response bodies.
• Self-hosted HTTP collects nothing unless you set APPLICATIONINSIGHTS_CONNECTION_STRING to your own resource — then the same minimal set flows to your instance instead.

Development

pip install -e ".[dev]"
pytest                  # offline suite (mocked feeds)
pytest --run-live       # also run live smoke tests against the real MSRC / EPSS / KEV APIs
ruff check src/ tests/

License

MIT