{"id":"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.","aliases":["GHSA-j975-95f5-7wqh"],"modified":"2026-04-10T05:32:04.968215Z","published":"2025-07-04T22:03:46.893Z","database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-248"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/53xxx/CVE-2025-53365.json"},"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"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/modelcontextprotocol/python-sdk","events":[{"introduced":"0"},{"fixed":"dced22344d80d85884df9c26281fdfe0331e9c65"}]}],"versions":["v1.0.0","v1.4.0","v1.4.1","v1.5.0","v1.6.0","v1.7.0","v1.8.0","v1.8.1","v1.9.0","v1.9.1","v1.9.2","v1.9.3","v1.9.4"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-53365.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"}]}