CVE-2025-53366
2 advisories.
PyPI/mcp CVE-2025-53366: high, EPSS 9.75%
MCP Python SDK vulnerability in the FastMCP Server causes validation error, leading to DoS
Action: Upgrade mcp to 1.9.4 or later.
pip install mcp==1.9.4Affected
| introduced | fixed | last affected |
|---|---|---|
| 0 | 1.9.4 | - |
Fixed versions
| 1.9.4 |
Sources
- osv: GHSA-3qhf-m339-9g5v
- https://github.com/modelcontextprotocol/python-sdk/security/advisories/GHSA-3qhf-m339-9g5v
- https://nvd.nist.gov/vuln/detail/CVE-2025-53366
- https://github.com/modelcontextprotocol/python-sdk/pull/822
- https://github.com/modelcontextprotocol/python-sdk/commit/29c69e6a47d0104d0afcea6ac35e7ab02fde809a
- https://github.com/advisories/GHSA-3qhf-m339-9g5v
- https://github.com/modelcontextprotocol/python-sdk
- https://github.com/modelcontextprotocol/python-sdk/releases/tag/v1.9.4
- https://github.com/pypa/advisory-database/tree/main/vulns/mcp/PYSEC-2026-1616.yaml
- https://pypi.org/project/mcp
CVE-2025-53366 · published · modified · JSON
PyPI/mcp CVE-2025-53366: unknown, EPSS 9.75%
MCP Python SDK vulnerability in the FastMCP Server causes validation error, leading to DoS
Action: Upgrade mcp to 1.9.4 or later.
pip install mcp==1.9.4Affected
| introduced | fixed | last affected |
|---|---|---|
| 0 | 1.9.4 | - |
Fixed versions
| 1.9.4 |
Sources
- osv: PYSEC-2026-1616
- https://github.com/modelcontextprotocol/python-sdk/security/advisories/GHSA-3qhf-m339-9g5v
- https://nvd.nist.gov/vuln/detail/CVE-2025-53366
- https://github.com/modelcontextprotocol/python-sdk/pull/822
- https://github.com/modelcontextprotocol/python-sdk/commit/29c69e6a47d0104d0afcea6ac35e7ab02fde809a
- https://github.com/modelcontextprotocol/python-sdk
- https://github.com/modelcontextprotocol/python-sdk/releases/tag/v1.9.4
- https://pypi.org/project/mcp
- https://github.com/advisories/GHSA-3qhf-m339-9g5v
CVE-2025-53366 · published · modified · JSON