{"id":"CVE-2025-53365","state":"PUBLISHED","title":"MCP Python SDK has Unhandled Exception in Streamable HTTP Transport ,Leading to Denial of Service","description":"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.","publishedAt":"2025-07-04T22:03:46.893Z","updatedAt":"2025-07-08T13:53:36.518Z","severity":{"score":8.7,"label":"High","version":"4.0","vector":"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","source":"GitHub_M"},"assigner":"GitHub_M","products":["modelcontextprotocol python-sdk"],"affected":[{"vendor":"modelcontextprotocol","product":"python-sdk","versions":[{"version":"< 1.10.0","status":"affected"}]}],"references":["https://github.com/modelcontextprotocol/python-sdk/security/advisories/GHSA-j975-95f5-7wqh","https://github.com/modelcontextprotocol/python-sdk/pull/967","https://github.com/modelcontextprotocol/python-sdk/commit/7b420656de48cfdb90b39eb582e60b6d55c2f891"],"weaknesses":["CWE-248"],"ingestedAt":"2026-10-29T20:09:31.862Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2025/53xxx/CVE-2025-53365.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.1","cveMetadata":{"cveId":"CVE-2025-53365","state":"PUBLISHED","datePublished":"2025-07-04T22:03:46.893Z","dateUpdated":"2025-07-08T13:53:36.518Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2025-06-27T12:57:16.121Z"},"containers":{"cna":{"title":"MCP Python SDK has Unhandled Exception in Streamable HTTP Transport ,Leading to Denial of Service","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"modelcontextprotocol","product":"python-sdk","versions":[{"version":"< 1.10.0","status":"affected"}]}],"references":[{"url":"https://github.com/modelcontextprotocol/python-sdk/security/advisories/GHSA-j975-95f5-7wqh","name":"https://github.com/modelcontextprotocol/python-sdk/security/advisories/GHSA-j975-95f5-7wqh","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/modelcontextprotocol/python-sdk/pull/967","name":"https://github.com/modelcontextprotocol/python-sdk/pull/967","tags":["x_refsource_MISC"]},{"url":"https://github.com/modelcontextprotocol/python-sdk/commit/7b420656de48cfdb90b39eb582e60b6d55c2f891","name":"https://github.com/modelcontextprotocol/python-sdk/commit/7b420656de48cfdb90b39eb582e60b6d55c2f891","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"HIGH","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":8.7,"baseSeverity":"HIGH","vectorString":"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","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-248","lang":"en","description":"CWE-248: Uncaught Exception","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2025-07-04T22:03:46.893Z"},"source":{"advisory":"GHSA-j975-95f5-7wqh","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2025-07-08T13:53:26.324368Z","id":"CVE-2025-53365","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2025-07-08T13:53:36.518Z"}}]}}}