PyPIPackage

fastmcp

8 known vulnerabilities (1 critical, 2 high, 5 medium), with the versions each affects and the releases that fix them.

Latest release: 4.1.6 (Nov 3, 2026): no advisory affects it
Newest unaffected release: 4.1.6 (Nov 3, 2026), the latest release
Advisories: 8 · 1 critical, 2 high, 5 medium

Weekly downloads: 13.1M
Releases: 142 since 0.1.0 (Nov 30, 2024)
Registry: PyPI
Releases read: Nov 8, 2026

Version timeline

GHSA-7XGJ-8392-5Q4R
Affects 3.0.0 to 3.4.9 (3.4.10 is outside it); 4.0.0 to 4.1.1 (4.1.2 is outside it)
GHSA-VQQP-X5QM-5QP4
Affects 4.0.0a1 to 4.1.1 (4.1.2 is outside it)
CVE-2026-27124
Affects 0.1.0 to 3.1.1 (3.2.0 is outside it)
CVE-2025-64340
Affects 0.1.0 to 3.1.1 (3.2.0 is outside it)
CVE-2026-32871
Affects 0.1.0 to 3.1.1 (3.2.0 is outside it)
CVE-2025-69196
Affects 0.1.0 to 2.14.1 (2.14.2 is outside it)
CVE-2025-62801
Affects 0.1.0 to 2.13.0rc3 (2.13.0 is outside it)
CVE-2025-62800
Affects 0.1.0 to 2.13.0rc3 (2.13.0 is outside it)

Every release cve.now has on record, lowest version on the left; each bar is a run of versions an advisory affects.

Advisories 8

GHSA-7XGJ-8392-5Q4RMedium
FastMCP: Post-transform component authorization is skipped on direct calls
Affected: from 3.0.0, fixed in 3.4.10; from 4.0.0, fixed in 4.1.2.
Fixed in 3.4.10 (released Oct 20, 2026, 3 days before disclosure) and 4.1.2 (released Oct 20, 2026, 3 days before disclosure).
The latest release, 4.1.6, is not affected.
GHSA-VQQP-X5QM-5QP4Medium
FastMCP MCP client wrappers construct M2M OAuth providers without issuer binding — client secret redirectable to attacker-advertised authori
Affected: from 4.0.0a1, fixed in 4.1.2.
Fixed in 4.1.2 (released Oct 20, 2026, 3 days before disclosure).
The latest release, 4.1.6, is not affected.
CVE-2026-27124High 8.2
FastMCP: Missing Consent Verification in OAuth Proxy Callback Facilitates Confused Deputy Vulnerabilities
Affected: fixed in 3.2.0.
Fixed in 3.2.0 (released Mar 30, 2026, 4 days before disclosure).
The latest release, 4.1.6, is not affected.
CVE-2025-64340Medium 6.7
FastMCP has a Command Injection vulnerability - Gemini CLI
Affected: fixed in 3.2.0.
Fixed in 3.2.0 (released Mar 30, 2026, 4 days before disclosure).
The latest release, 4.1.6, is not affected.
CVE-2026-32871Critical 10.0
FastMCP OpenAPI Provider has an SSRF & Path Traversal Vulnerability
Affected: fixed in 3.2.0.
Fixed in 3.2.0 (released Mar 30, 2026, 3 days before disclosure).
The latest release, 4.1.6, is not affected.
CVE-2025-69196High 7.4
FastMCP OAuth Proxy token reuse across MCP servers
Affected: fixed in 2.14.2.
Fixed in 2.14.2 (released Dec 31, 2025, 75 days before disclosure).
The latest release, 4.1.6, is not affected.
CVE-2025-62801Medium 5.4
FastMCP vulnerable to windows command injection in FastMCP Cursor installer via server_name
Affected: fixed in 2.13.0.
Fixed in 2.13.0 (released Oct 25, 2025, 3 days before disclosure).
The latest release, 4.1.6, is not affected.
CVE-2025-62800Medium 5.3
FastMCP vulnerable to reflected XSS in client's callback page
Affected: fixed in 2.13.0.
Fixed in 2.13.0 (released Oct 25, 2025, 3 days before disclosure).
The latest release, 4.1.6, is not affected.