MCP Python SDK vulnerability in the FastMCP Server causes validation error, leading to DoS

GHSA-3qhf-m339-9g5v · CVE-2025-53366 · PYSEC-2026-1616 · 갱신 2026. 7. 17.

해야 할 일

mcp: 1.9.4 이상으로 올리세요.

영향 받는 패키지

생태계	패키지	수정 버전
PyPI	mcp	1.9.4

원문

MCP Python SDK vulnerability in the FastMCP Server causes validation error, leading to DoS

A validation error in the MCP SDK can cause an unhandled exception when processing malformed requests, resulting in service unavailability (500 errors) until manually restarted. Impact may vary depending on the deployment conditions, and presence of infrastructure-level resilience measures.

Thank you to Rich Harang for reporting this issue.

출처

WEBhttps://github.com/modelcontextprotocol/python-sdk/security/advisories/GHSA-3qhf-m339-9g5v
ADVISORYhttps://nvd.nist.gov/vuln/detail/CVE-2025-53366
WEBhttps://github.com/modelcontextprotocol/python-sdk/pull/822
WEBhttps://github.com/modelcontextprotocol/python-sdk/commit/29c69e6a47d0104d0afcea6ac35e7ab02fde809a
ADVISORYhttps://github.com/advisories/GHSA-3qhf-m339-9g5v
PACKAGEhttps://github.com/modelcontextprotocol/python-sdk
WEBhttps://github.com/modelcontextprotocol/python-sdk/releases/tag/v1.9.4
WEBhttps://github.com/pypa/advisory-database/tree/main/vulns/mcp/PYSEC-2026-1616.yaml

오늘 목록으로

MCP Python SDK vulnerability in the FastMCP Server causes validation error, leading to DoS (GHSA-3qhf-m339-9g5v) · Sieve