Patch Tuesday

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

Patch Tuesday MCP Server

[patch-tuesday-mcp MCP server] [PyPI] [MCP Registry] [License: MIT]

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• Avoid stale patches - "Is KB5087538 superseded by anything newer?"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
• Filter by Microsoft's own exploitation forecast - "Which of this month's CVEs does Microsoft rate 'Exploitation More Likely'?" (exploitation_likely=True)
• Spot ransomware-weaponized CVEs - "Which CVEs this month are used in known ransomware campaigns?" (ransomware=True; add include_kev_details=True for the full CISA entry with required actions)
• Plan the deployment, not just the priority - "Does KB5094123 require a restart, and what build fixes it?" (include_kb_details=True adds per-KB URLs, fixed builds, supersedence, and restart requirements)
• Know what Microsoft says an update breaks - "Any known issues with KB5094126 before I roll it out?" (include_known_issues=True adds each KB's Microsoft-confirmed known issues — symptoms, workarounds, and the resolving update — best-effort from its public support page; published mainly for Windows updates, and the response says explicitly when Microsoft publishes none)
• Know what an update changes, not just what it fixes - "What's actually in KB5099536 besides the security fixes?" (include_update_summary=True adds the KB support page's summary and improvements highlights — the change-description content the MSRC security data doesn't carry — from the same page fetch as the known-issues lookup)
• Slice a month by weakness class - "Show me this month's use-after-free CVEs" (cwe="CWE-416" or cwe="use after free")
• Discover the release catalog - "Which monthly releases are available, and when were they last revised?" (list_months=True)
• 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:

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.agreeabledesert-d0b8e491.eastus2.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 / Linuxcurl -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

[Set up in VS Code] [Set up in Cursor] [Set up in Claude Code] [Set up in Copilot CLI]

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). Pass a list of KB numbers (kb=["5094123", "KB5094127", ...], up to 30) to resolve them all in one call — e.g. a machine's installed-update list as context for a patch report — and get a grouped response with one per-KB entry (found or not-found, each with the same body as a single-KB lookup); every monthly document is still fetched upstream at most once for the whole batch. Add include_known_issues=True to any KB lookup (single or batched) for the Microsoft-confirmed known issues of each update — issue titles, symptoms, workarounds, and the resolving KB when Microsoft names one — scraped best-effort from the KB's public support page with an honest per-KB status: published, none_published (Microsoft publishes no known-issues data for that KB — the norm outside Windows OS updates), or unavailable (retrieval/parse failure, explicitly distinct from "no issues"); it reports what Microsoft has confirmed breaks, not a prediction for your environment. Add include_update_summary=True to a KB lookup for what the update changes — the support page's Summary/Highlights text plus its Improvements bullet list (size-capped, truncated marks a capped block) with the same honest three-way status; both support-page blocks are served by a single fetch and one shared cache record. 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. Filter on Microsoft's exploitation-likelihood assessment with exploitation_likely=True ("Exploitation More Likely"/"Exploitation Detected"; matches carry an exploitation_assessment field) and on known ransomware campaign use with ransomware=True (from the CISA KEV catalog). Opt into richer rows where you need them: include_references=True adds the MSRC/NVD/EPSS/KEV link block to month/KB/trend list results, include_kev_details=True replaces the boolean KEV flag with the full catalog entry (due date, required action, vendor/product, ransomware use), include_kb_details=True expands KB numbers into full objects with per-KB URL, fixed build, supersedence, sub-type, and restart-required status, and include_temporal=True adds Microsoft's CVSS temporal score to cvss blocks. Filter by weakness class with cwe= (ID or name substring, e.g. cwe="CWE-416"). Use list_months=True to fetch the release catalog (every available month with initial/current release dates — handy for valid month= values and spotting same-month revisions). All new fields are opt-in: the default JSON shape is unchanged.

Product profiles (watchlists)

Scope any search to the products you actually run. Pass product_profile="identity-core" (built-in profiles: identity-core, endpoint, server-infrastructure) or supply ad-hoc products=["Exchange Server", "Windows Server"] / product_families=["Windows", "Azure"]. A vulnerability is kept if it matches any listed product or family. All matching is local — profile contents are never transmitted to MSRC, FIRST.org, CISA, or telemetry.

Override or extend the built-ins by pointing MSRC_PROFILES_PATH at a JSON file:

{  "my-estate": {    "families": ["Windows", "Azure"],    "products": ["Exchange Server", "Microsoft Entra"]  }}

Each entry may set products and/or families (case-insensitive partial matchers). A file entry with the same name as a built-in replaces it. An unknown product_profile, or a missing/invalid MSRC_PROFILES_PATH, returns a clear invalid_input error rather than falling back to a broad, unscoped result.

Companion triage skill

A portable agent skill — patch-tuesday-triage — teaches an AI agent how to drive msrc_search through the monthly workflow (which searches to run, in what order, how to prioritize). It's plain Markdown and can be deployed independently of this server: copy skills/patch-tuesday-triage/ into your agent's skills directory. See skills/README.md for deployment details.

Guided triage prompt

The server registers an MCP prompt named monthly_triage. MCP clients that support prompts can select it to get a step-by-step analyst workflow built entirely on msrc_search — publicly disclosed zero-days, CISA KEV, exploited, network/no-auth/no-UI criticals, identity-adjacent products, endpoint/Intune, and a briefing. It accepts two optional arguments: product_profile (scope the whole workflow to a watchlist) and month (triage a specific release). No new tools are introduced — the prompt only orchestrates msrc_search calls.

A portable, plain-text copy of this prompt lives under prompts/ so the workflow can be used independently of the server.

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. Machine patch report: "Here are the KBs installed on this server: KB5094123, KB5094127, KB5093998 — what do they fix and is anything superseded?"
6. Product filter: "Show me Critical vulnerabilities affecting Exchange Server this month"
7. Patch prioritization: "What should I patch first from the June 2026 updates?"
8. CISA KEV: "Which of this month's CVEs are on the CISA KEV list?"
9. EPSS: "Show me CVEs with EPSS above 50%"
10. Exposure filtering: "Which Critical CVEs are network-reachable with no privileges and no user interaction?"
11. Reference links: "Give me the MSRC, NVD, and EPSS links for CVE-2026-41108"
12. Mitigations & workarounds: "Are there any mitigations or workarounds for CVE-2026-41108?"
13. Triage report: "Give me this month's Critical CVEs as a Markdown briefing" (or "…export them as CSV")
14. 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)
15. Historical trends: "How many HTTP.sys RCE CVEs shipped over the last 6 months?" (query="HTTP.sys", months_back=6)
16. Supersedence: "Is KB5087538 superseded by anything newer?"
17. Exploitation forecast: "Which CVEs does Microsoft rate 'Exploitation More Likely' this month?"
18. Ransomware: "Which of this month's CVEs are used in known ransomware campaigns?"
19. Deployment planning: "Does KB5094123 require a restart, and which build fixes it?"
20. Known issues before rollout: "What has Microsoft confirmed breaks in KB5094126, and is there a fix or workaround?" (include_known_issues=True)
21. What's in an update: "Summarize what KB5099536 changes beyond the security fixes" (include_update_summary=True)
22. Weakness class: "Show me this month's use-after-free vulnerabilities" (cwe="CWE-416")
23. Release catalog: "Which Patch Tuesday months are available to query?"
24. Product watchlist: "Show me this month's Critical CVEs across my estate" (product_profile="identity-core", severity="Critical")
25. Guided triage: "Walk me through this month's triage for my identity estate" (selects the monthly_triage prompt with product_profile="identity-core")

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:

Announcing a deprecation (self-hosters)

If you are retiring a deployment, set MCP_DEPRECATION_SUNSET and MCP_DEPRECATION_REPLACEMENT_URL on that deployment only. The server then reports the migration through four channels:

• a deprecation block on every msrc_search response (and on /health)
• Deprecation, Sunset, and Link: <url>; rel="successor-version" response headers (RFC 9745, RFC 8594, RFC 5829)
• the MCP server instructions shown to clients at connection time
• the msrc_search tool description

All of it is descriptive: it states facts about the deployment. It never instructs a connected agent to say or do anything — tool output that issues directives to someone else's model is prompt injection, however benign the payload. Leave the variables unset and behavior is byte-for-byte unchanged; setting only one of the two pair, or a malformed date, is ignored.

HTTP mode also serves GET /health (liveness endpoint) 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.
• Keep the defaults on. Leave MCP_MAX_BODY_BYTES and MCP_LIMIT_CONCURRENCY at their defaults (or tighten them) — they are your first line of defense against oversized payloads and connection exhaustion.
• Upstream reads are bounded and redirect-free. Responses from MSRC/EPSS/ KEV are size-capped while streaming and HTTP redirects are never followed, so a misbehaving upstream can't exhaust container memory.

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 APIspytest --cov=patch_tuesday_mcp   # coverage (CI enforces >= 90%)ruff check src/ tests/

CI (GitHub Actions) runs the offline suite on Python 3.11/3.12/3.14 with a coverage gate, lints with ruff, builds the container, scans it with Trivy, and produces an SPDX SBOM on every push/PR. Release builds attest provenance for the published wheel/sdist. Dependencies are locked in uv.lock (used by the Docker build via uv sync --locked).

Security

See SECURITY.md for the supported versions, scope, and how to report a vulnerability privately.

License

MIT