Source: python-mcp Version: 1.28.1-1 X-Debbugs-CC: [email protected] Severity: grave Tags: security upstream
Hi, The following vulnerability was published for python-mcp. CVE-2026-59951[0]: | The MCP Python SDK, called mcp on PyPI, is a Python implementation | of the Model Context Protocol (MCP). From 1.8.0 until 1.30.0 and | 2.2.0, stateful Streamable HTTP servers, including FastMCP, | MCPServer, Server.streamable_http_app(), and | StreamableHTTPSessionManager, retain session entries without an idle | expiration or aggregate session-count limit. DELETE, refused opening | requests, and completed sessions do not reliably discard their | entries, and each entry can retain parsed initialize parameters. A | client that can reach the endpoint can therefore create ordinary | short requests that grow server memory without bound until restart. | Stateless HTTP, stdio, and SSE transports are not affected. This | issue is fixed in versions 1.30.0 and 2.2.0. If you fix the vulnerability please also make sure to include the CVE (Common Vulnerabilities & Exposures) id in your changelog entry. For further information see: [0] https://security-tracker.debian.org/tracker/CVE-2026-59951 https://www.cve.org/CVERecord?id=CVE-2026-59951 [1] https://github.com/modelcontextprotocol/python-sdk/security/advisories/GHSA-84m7-p3x7-pcfv [2] https://github.com/modelcontextprotocol/python-sdk/pull/3395 [3] https://github.com/modelcontextprotocol/python-sdk/pull/3426 [4] https://github.com/modelcontextprotocol/python-sdk/commit/92120b4b0f50385af096592d7cee932fc1d994e7 Regards, Salvatore
