CVE-2025-66416
Model Context Protocol (MCP) Python SDK does not enable DNS rebinding protection by default
描述
### Description The Model Context Protocol (MCP) Python SDK does not enable DNS rebinding protection by default for HTTP-based servers. When an HTTP-based MCP server is run on localhost without authentication using `FastMCP` with streamable HTTP or SSE transport, and has not configured `TransportSecuritySettings`, a malicious website could exploit DNS rebinding to bypass same-origin policy restrictions and send requests to the local MCP server. This could allow an attacker to invoke tools or access resources exposed by the MCP server on behalf of the user in those limited circumstances. Note that running HTTP-based MCP servers locally without authentication is not recommended per MCP security best practices. This issue does not affect servers using stdio transport. Servers created via `FastMCP()` now have DNS rebinding protection enabled by default when the `host` parameter is `127.0.0.1` or `localhost`. Users are advised to update to version `1.23.0` to receive this automatic protection. Users with custom low-level server configurations using `StreamableHTTPSessionManager` or `SseServerTransport` directly should explicitly configure `TransportSecuritySettings` when running an unauthenticated server on localhost.
如何修補 CVE-2025-66416
要修補 CVE-2025-66416,請將受影響套件升級到下列已修補版本。
- —升級至 1.23.0 或更新版本
CVE-2025-66416 正在被利用嗎?
低 — EPSS 為 0.5%,目前沒有觀察到大規模利用活動。
受影響套件(1)
- from 0, < 1.23.0
CVSS 分數
| 來源 | 版本 | 嚴重程度 | 向量 |
|---|---|---|---|
| osv | CVSS 4.0 | — | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N |