Vulnerability in functype-mcp-server (CVE-2026-59176)
Summary
Vulnerability in functype-mcp-server (CVE-2026-59176). Risk of unauthorized operations or information disclosure. Exploitable via set_functype_version. Mitigation: upgrade to 1.4.4 or later.
Original description
The description as published by the source.
MCP set_functype_version Package Alias RCE via Unsanitized pnpm install + Dynamic Import
Summary
The set_functype_version MCP tool in functype-mcp-server accepts an unconstrained version string, interpolates it directly into an npm package specifier (functype@), and installs it via pnpm add without any validation. Because npm/pnpm package specifiers support file:, npm:, and other alias syntaxes, an attacker who can send an MCP tools/call request to this tool can cause the server to install an arbitrary local or remote package as functype. Immediately after installation, the server calls initDocsData(true), which dynamically imports functype/cli from the newly installed location, executing attacker-controlled JavaScript in the MCP server process. This results in full Remote Code Execution (RCE) with the privileges of the server process — full confidentiality, integrity, and availability impact (CVSS 7.8 High).
Details
The vulnerable code is in packages/mcp-server/src/index.ts. The set_functype_version tool is registered at line 115 and is enabled by default (no authentication required in stdio mode).
Source (user input accepted without validation):
// packages/mcp-server/src/index.ts:119-121
parameters: z.object({
version: z.string().describe('The functype version to install (e.g., "0.46.0", "latest", "^0.45.0")'),
}),
Only z.string() validation is applied — no semver format check, no allowlist for dist-tags, and no…
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-59176 has been found in functype-mcp-server.
Attackers can target a specific entry point like set_functype_version over the network to misuse the product.
Risk of unauthorized operations or information disclosure.
What to do: upgrade functype-mcp-server to 1.4.4 or later.
If unsure, ask your IT team or search "functype-mcp-server CVE-2026-59176" on the vendor's site.
CVE-2026-59176 (functype-mcp-server) — CWE-829
Attack surface: set_functype_version / version / functype / args.version
Patched: 1.4.4 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-829) exists in functype-mcp-server. Attackers reach the vulnerable code path via set_functype_version.
Check the vendor advisory for the affected versions of functype-mcp-server. Attack surface: set_functype_version / version / functype / args.version.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to 1.4.4.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'functype-mcp-server' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'functype-mcp-server' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
functype-mcp-serverを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade functype-mcp-server to 1.4.4ステージング環境で 1.4.4 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- web github.com
- web github.com
- web github.com