{"id":"CVE-2025-53365","aliases":["GHSA-j975-95f5-7wqh","PYSEC-2026-1618"],"url":"https://o3.security/vulnerability/CVE-2025-53365","summary":"MCP Python SDK has Unhandled Exception in Streamable HTTP Transport ,Leading to Denial of Service","details":"The MCP Python SDK, called `mcp` on PyPI, is a Python implementation of the Model Context Protocol (MCP). Prior to version 1.10.0, if a client deliberately triggers an exception after establishing a streamable HTTP session, this can lead to an uncaught ClosedResourceError on the server side, causing the server to crash and requiring a restart to restore service. Impact may vary depending on the deployment conditions, and presence of infrastructure-level resilience measures. Version 1.10.0 contains a patch for the issue.","published":"2025-07-04T22:03:46.893Z","modified":"2026-08-12T03:51:19.624554636Z","cvss":null,"epss":{"score":0.00367,"percentile":0.30411,"asOf":"2026-09-17"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"mcp","fixedVersion":"1.10.0"}],"fix":{"url":"https://github.com/modelcontextprotocol/python-sdk/commit/7b420656de48cfdb90b39eb582e60b6d55c2f891","label":"modelcontextprotocol/python-sdk@7b42065"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/53xxx/CVE-2025-53365.json"},{"type":"ADVISORY","url":"https://github.com/modelcontextprotocol/python-sdk/security/advisories/GHSA-j975-95f5-7wqh"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-53365"},{"type":"FIX","url":"https://github.com/modelcontextprotocol/python-sdk/commit/7b420656de48cfdb90b39eb582e60b6d55c2f891"},{"type":"FIX","url":"https://github.com/modelcontextprotocol/python-sdk/pull/967"},{"type":"ADVISORY","url":"https://github.com/advisories/GHSA-j975-95f5-7wqh"},{"type":"PACKAGE","url":"https://github.com/modelcontextprotocol/python-sdk"},{"type":"WEB","url":"https://github.com/modelcontextprotocol/python-sdk/releases/tag/v1.10.0"},{"type":"WEB","url":"https://github.com/pypa/advisory-database/tree/main/vulns/mcp/PYSEC-2026-1618.yaml"},{"type":"WEB","url":"https://pypi.org/project/mcp"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:19.624554636Z"}}