{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-109527", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-10-12T19:11:21.789Z", "datePublished": "2026-10-14T17:52:35.943Z", "dateUpdated": "2026-10-14T17:52:35.943Z"}, "containers": {"cna": {"title": "Model Context Protocol Python SDK HTTP and OAuth endpoints allow memory exhaustion through unbounded request bodies", "problemTypes": [{"descriptions": [{"cweId": "CWE-770", "lang": "en", "description": "CWE-770: Allocation of Resources Without Limits or Throttling", "type": "CWE"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}}], "references": [{"name": "https://github.com/modelcontextprotocol/python-sdk/security/advisories/GHSA-fmmv-w9g8-j3gc", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/modelcontextprotocol/python-sdk/security/advisories/GHSA-fmmv-w9g8-j3gc"}, {"name": "https://github.com/modelcontextprotocol/python-sdk/commit/03aaebd3aadb2567878dd811cb1f141454e8a080", "tags": ["x_refsource_MISC"], "url": "https://github.com/modelcontextprotocol/python-sdk/commit/03aaebd3aadb2567878dd811cb1f141454e8a080"}, {"name": "https://github.com/modelcontextprotocol/python-sdk/commit/4dc224fab201bdef2fd5a065976b7ca31420187c", "tags": ["x_refsource_MISC"], "url": "https://github.com/modelcontextprotocol/python-sdk/commit/4dc224fab201bdef2fd5a065976b7ca31420187c"}, {"name": "https://github.com/modelcontextprotocol/python-sdk/commit/57394b0548d1e2dc2dce8d67d84985769df3b8bb", "tags": ["x_refsource_MISC"], "url": "https://github.com/modelcontextprotocol/python-sdk/commit/57394b0548d1e2dc2dce8d67d84985769df3b8bb"}, {"name": "https://github.com/modelcontextprotocol/python-sdk/commit/5f0b6af9f2b0aad3be3ba5cbfe80a9e4ea32e189", "tags": ["x_refsource_MISC"], "url": "https://github.com/modelcontextprotocol/python-sdk/commit/5f0b6af9f2b0aad3be3ba5cbfe80a9e4ea32e189"}, {"name": "https://github.com/modelcontextprotocol/python-sdk/releases/tag/v1.29.1", "tags": ["x_refsource_MISC"], "url": "https://github.com/modelcontextprotocol/python-sdk/releases/tag/v1.29.1"}, {"name": "https://github.com/modelcontextprotocol/python-sdk/releases/tag/v2.1.0", "tags": ["x_refsource_MISC"], "url": "https://github.com/modelcontextprotocol/python-sdk/releases/tag/v2.1.0"}], "affected": [{"vendor": "modelcontextprotocol", "product": "python-sdk", "versions": [{"version": "< 1.29.1", "status": "affected"}, {"version": ">= 2.0.0a1, < 2.1.0", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-10-14T17:52:35.943Z"}, "descriptions": [{"lang": "en", "value": "The Model Context Protocol Python SDK is the official Python SDK for Model Context Protocol servers and clients. In mcp versions before 1.29.1 and from 2.0.0a1 through 2.0.1, the Streamable HTTP session manager, SSE message endpoint, and OAuth authorization-server routes buffer complete HTTP request bodies without enforcing a maximum size. An unauthenticated remote client able to reach an affected endpoint can send a large declared or streamed request body that consumes multiple times the body size in process memory and can repeatedly exhaust memory or terminate the server. Stdio-only servers and deployments with an effective upstream request-size limit are not affected, and applications that use StreamableHTTPServerTransport directly remain responsible for enforcing their own limit. The standard SDK server applications and session managers are fixed in versions 1.29.1 and 2.1.0."}], "source": {"advisory": "GHSA-fmmv-w9g8-j3gc", "discovery": "UNKNOWN"}}}}

{}

{"affected": [{"affectedData": [{"product": "python-sdk", "vendor": "modelcontextprotocol", "versions": [{"status": "affected", "version": "< 1.29.1"}, {"status": "affected", "version": ">= 2.0.0a1, < 2.1.0"}]}], "source": "security-advisories@github.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "The Model Context Protocol Python SDK is the official Python SDK for Model Context Protocol servers and clients. In mcp versions before 1.29.1 and from 2.0.0a1 through 2.0.1, the Streamable HTTP session manager, SSE message endpoint, and OAuth authorization-server routes buffer complete HTTP request bodies without enforcing a maximum size. An unauthenticated remote client able to reach an affected endpoint can send a large declared or streamed request body that consumes multiple times the body size in process memory and can repeatedly exhaust memory or terminate the server. Stdio-only servers and deployments with an effective upstream request-size limit are not affected, and applications that use StreamableHTTPServerTransport directly remain responsible for enforcing their own limit. The standard SDK server applications and session managers are fixed in versions 1.29.1 and 2.1.0."}], "id": "CVE-2026-109527", "lastModified": "2026-10-16T16:00:33.533", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 3.6, "source": "security-advisories@github.com", "type": "Secondary"}]}, "published": "2026-10-14T18:17:33.447", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/modelcontextprotocol/python-sdk/commit/03aaebd3aadb2567878dd811cb1f141454e8a080"}, {"source": "security-advisories@github.com", "url": "https://github.com/modelcontextprotocol/python-sdk/commit/4dc224fab201bdef2fd5a065976b7ca31420187c"}, {"source": "security-advisories@github.com", "url": "https://github.com/modelcontextprotocol/python-sdk/commit/57394b0548d1e2dc2dce8d67d84985769df3b8bb"}, {"source": "security-advisories@github.com", "url": "https://github.com/modelcontextprotocol/python-sdk/commit/5f0b6af9f2b0aad3be3ba5cbfe80a9e4ea32e189"}, {"source": "security-advisories@github.com", "url": "https://github.com/modelcontextprotocol/python-sdk/releases/tag/v1.29.1"}, {"source": "security-advisories@github.com", "url": "https://github.com/modelcontextprotocol/python-sdk/releases/tag/v2.1.0"}, {"source": "security-advisories@github.com", "url": "https://github.com/modelcontextprotocol/python-sdk/security/advisories/GHSA-fmmv-w9g8-j3gc"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Awaiting Analysis", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-770"}], "source": "security-advisories@github.com", "type": "Primary"}]}

{"bugzilla": {"description": "mcp: mcp: Denial of Service via unbounded HTTP request body buffering", "id": "2552745", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2552745"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.5", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-770", "details": ["A flaw was found in mcp. This vulnerability allows an unauthenticated remote attacker to cause a Denial of Service (DoS) by exhausting system memory. Affected HTTP endpoints buffer incoming request bodies in memory without enforcing a maximum size limit. By sending excessively large or streamed request bodies, an attacker can consume significant process memory and terminate the server."], "name": "CVE-2026-109527", "package_state": [{"cpe": "cpe:/a:redhat:ansible_automation_orchestrator:2026.8", "fix_state": "Affected", "package_name": "ansible-automation-platform/automation-orchestrator-backend-rhel9", "product_name": "Ansible Automation Orchestrator 2026"}, {"cpe": "cpe:/a:redhat:exploit_intelligence:0", "fix_state": "Affected", "package_name": "exploit-intelligence/vulnerability-analysis-rhel9", "product_name": "Exploit Intelligence"}, {"cpe": "cpe:/a:redhat:lightspeed_core", "fix_state": "Affected", "package_name": "lightspeed-core/lightspeed-stack-rhel9", "product_name": "Lightspeed Core"}, {"cpe": "cpe:/a:redhat:lightspeed_core", "fix_state": "Affected", "package_name": "lightspeed-core/rag-tool-cpu-rhel9", "product_name": "Lightspeed Core"}, {"cpe": "cpe:/a:redhat:lightspeed_core", "fix_state": "Affected", "package_name": "lightspeed-core/rag-tool-cuda-12.9-rhel9", "product_name": "Lightspeed Core"}, {"cpe": "cpe:/a:redhat:migration_toolkit_applications:8", "fix_state": "Affected", "package_name": "mta/mta-solution-server-rhel9", "product_name": "Migration Toolkit for Applications 8"}, {"cpe": "cpe:/a:redhat:openshift_lightspeed:1", "fix_state": "Affected", "package_name": "openshift-lightspeed/lightspeed-agentic-sandbox-rhel9", "product_name": "OpenShift Lightspeed"}, {"cpe": "cpe:/a:redhat:openshift_lightspeed:1", "fix_state": "Affected", "package_name": "openshift-lightspeed/lightspeed-service-api-rhel9", "product_name": "OpenShift Lightspeed"}, {"cpe": "cpe:/a:redhat:ai_inference_server:3", "fix_state": "Affected", "package_name": "rhaiis/vllm-cpu-rhel9", "product_name": "Red Hat AI Inference Server"}, {"cpe": "cpe:/a:redhat:ai_inference_server:3", "fix_state": "Affected", "package_name": "rhaiis/vllm-cuda-rhel9", "product_name": "Red Hat AI Inference Server"}, {"cpe": "cpe:/a:redhat:ai_inference_server:3", "fix_state": "Affected", "package_name": "rhaiis/vllm-rocm-rhel9", "product_name": "Red Hat AI Inference Server"}, {"cpe": "cpe:/a:redhat:ai_inference_server:3", "fix_state": "Affected", "package_name": "rhaiis/vllm-tpu-rhel9", "product_name": "Red Hat AI Inference Server"}, {"cpe": "cpe:/a:redhat:ai_inference_server:3", "fix_state": "Affected", "package_name": "rhaii/vllm-cpu-rhel9", "product_name": "Red Hat AI Inference Server"}, {"cpe": "cpe:/a:redhat:ai_inference_server:3", "fix_state": "Affected", "package_name": "rhaii/vllm-cuda-rhel9", "product_name": "Red Hat AI Inference Server"}, {"cpe": "cpe:/a:redhat:ai_inference_server:3", "fix_state": "Affected", "package_name": "rhaii/vllm-gaudi-rhel9", "product_name": "Red Hat AI Inference Server"}, {"cpe": "cpe:/a:redhat:ai_inference_server:3", "fix_state": "Affected", "package_name": "rhaii/vllm-neuron-rhel9", "product_name": "Red Hat AI Inference Server"}, {"cpe": "cpe:/a:redhat:ai_inference_server:3", "fix_state": "Affected", "package_name": "rhaii/vllm-rocm-rhel9", "product_name": "Red Hat AI Inference Server"}, {"cpe": "cpe:/a:redhat:ai_inference_server:3", "fix_state": "Affected", "package_name": "rhaii/vllm-spyre-rhel9", "product_name": "Red Hat AI Inference Server"}, {"cpe": "cpe:/a:redhat:ai_inference_server:3", "fix_state": "Affected", "package_name": "rhaii/vllm-tpu-rhel9", "product_name": "Red Hat AI Inference Server"}, {"cpe": "cpe:/a:redhat:ansible_automation_platform:2", "fix_state": "Affected", "package_name": "ansible-automation-platform-26/lightspeed-chatbot-rhel9", "product_name": "Red Hat Ansible Automation Platform 2"}, {"cpe": "cpe:/a:redhat:ansible_automation_platform:2", "fix_state": "Affected", "package_name": "ansible-automation-platform-26/mcp-tools-rhel9", "product_name": "Red Hat Ansible Automation Platform 2"}, {"cpe": "cpe:/a:redhat:ansible_automation_platform:2", "fix_state": "Affected", "package_name": "ansible-automation-platform-27/lightspeed-chatbot-rhel9", "product_name": "Red Hat Ansible Automation Platform 2"}, {"cpe": "cpe:/a:redhat:ansible_automation_platform:2", "fix_state": "Affected", "package_name": "ansible-automation-platform-27/mcp-tools-rhel9", "product_name": "Red Hat Ansible Automation Platform 2"}, {"cpe": "cpe:/a:redhat:enterprise_linux_ai:3", "fix_state": "Affected", "package_name": "rhelai3/bootc-aws-cuda-rhel9", "product_name": "Red Hat Enterprise Linux AI (RHEL AI) 3"}, {"cpe": "cpe:/a:redhat:enterprise_linux_ai:3", "fix_state": "Affected", "package_name": "rhelai3/bootc-azure-cuda-rhel9", "product_name": "Red Hat Enterprise Linux AI (RHEL AI) 3"}, {"cpe": "cpe:/a:redhat:enterprise_linux_ai:3", "fix_state": "Affected", "package_name": "rhelai3/bootc-azure-rocm-rhel9", "product_name": "Red Hat Enterprise Linux AI (RHEL AI) 3"}, {"cpe": "cpe:/a:redhat:enterprise_linux_ai:3", "fix_state": "Affected", "package_name": "rhelai3/bootc-cuda-rhel9", "product_name": "Red Hat Enterprise Linux AI (RHEL AI) 3"}, {"cpe": "cpe:/a:redhat:enterprise_linux_ai:3", "fix_state": "Affected", "package_name": "rhelai3/bootc-gaudi-rhel9", "product_name": "Red Hat Enterprise Linux AI (RHEL AI) 3"}, {"cpe": "cpe:/a:redhat:enterprise_linux_ai:3", "fix_state": "Affected", "package_name": "rhelai3/bootc-gcp-cuda-rhel9", "product_name": "Red Hat Enterprise Linux AI (RHEL AI) 3"}, {"cpe": "cpe:/a:redhat:enterprise_linux_ai:3", "fix_state": "Affected", "package_name": "rhelai3/bootc-rocm-rhel9", "product_name": "Red Hat Enterprise Linux AI (RHEL AI) 3"}, {"cpe": "cpe:/a:redhat:rhel_cla:1", "fix_state": "Affected", "package_name": "rhel-cla/rhel-knowledge-bridge-rhel10", "product_name": "Red Hat Enterprise Linux command line assistant"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Affected", "package_name": "rhai-early-access/docling-serve-cuda-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Affected", "package_name": "rhoai/odh-feature-server-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Affected", "package_name": "rhoai/odh-kserve-agent-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Affected", "package_name": "rhoai/odh-kserve-controller-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Affected", "package_name": "rhoai/odh-kserve-router-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Affected", "package_name": "rhoai/odh-kserve-storage-initializer-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Affected", "package_name": "rhoai/odh-llama-stack-core-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Affected", "package_name": "rhoai/odh-llm-d-kv-cache-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Affected", "package_name": "rhoai/odh-ogx-core-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Affected", "package_name": "rhoai/odh-openvino-model-server-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Affected", "package_name": "rhoai/odh-th-torch-cuda-py312-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Affected", "package_name": "rhoai/odh-trustyai-garak-lls-provider-dsp-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Affected", "package_name": "rhoai/odh-vllm-gaudi-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:container_native_virtualization:4", "fix_state": "Affected", "package_name": "container-native-virtualization/ocp-virt-validation-checkup-rhel9", "product_name": "Red Hat OpenShift Virtualization 4"}, {"cpe": "cpe:/a:redhat:satellite:6", "fix_state": "Affected", "package_name": "satellite/foreman-mcp-server-rhel9", "product_name": "Red Hat Satellite 6"}], "public_date": "2026-10-14T17:52:35Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-109527\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-109527\nhttps://github.com/modelcontextprotocol/python-sdk/commit/03aaebd3aadb2567878dd811cb1f141454e8a080\nhttps://github.com/modelcontextprotocol/python-sdk/commit/4dc224fab201bdef2fd5a065976b7ca31420187c\nhttps://github.com/modelcontextprotocol/python-sdk/commit/57394b0548d1e2dc2dce8d67d84985769df3b8bb\nhttps://github.com/modelcontextprotocol/python-sdk/commit/5f0b6af9f2b0aad3be3ba5cbfe80a9e4ea32e189\nhttps://github.com/modelcontextprotocol/python-sdk/releases/tag/v1.29.1\nhttps://github.com/modelcontextprotocol/python-sdk/releases/tag/v2.1.0\nhttps://github.com/modelcontextprotocol/python-sdk/security/advisories/GHSA-fmmv-w9g8-j3gc"], "threat_severity": "Important"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,1.29.1)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[2.0.0a1,2.1.0)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "python-sdk", "source": "cna", "vendor": "modelcontextprotocol"}, "product": "python-sdk", "vendor": "modelcontextprotocol"}], "created": "2026-10-15T14:30:18.231605+00:00", "updated": "2026-10-17T09:30:05.821669+00:00", "vendors": ["modelcontextprotocol", "modelcontextprotocol$PRODUCT$python-sdk"]}