MCP Python SDK has Unhandled Exception in Streamable HTTP Transport ,Leading to Denial of Service
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 1 without a fix
Attack profile from CVSS 4.0 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-248.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| MLflow | python-sdk | before 1.10.0 | 1.10.0 | Patch available | CNA |
| — | mcp (PyPI) | before 1.10.0 | 1.10.0 | Patch available | GHSA-j975-95f5-7wqh |
- python-sdk VendorMLflow Affected before 1.10.0 Fixed in 1.10.0 Patch available CNA
- mcp (PyPI) Vendor— Affected before 1.10.0 Fixed in 1.10.0 Patch available GHSA-j975-95f5-7wqh
Remediation
- Fix · CNA python-sdk (modelcontextprotocol) Fixed in 1.10.0
- Fix · GHSA-j975-95f5-7wqh mcp (PyPI) Fixed in 1.10.0 Advisory →
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| OpenShift Lightspeed | Affected | No fix yet |
Timeline
- 2026-10-02 Threatist record created from CVE-2025-53365
- 2026-10-03 Alias added: GHSA-j975-95f5-7wqh
References
Advisory 2
Other 7
- 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
- https://github.com/modelcontextprotocol/python-sdk
- https://github.com/modelcontextprotocol/python-sdk/releases/tag/v1.10.0
- https://github.com/pypa/advisory-database/tree/main/vulns/mcp/PYSEC-2026-1618.yaml
- https://pypi.org/project/mcp
More MLflow vulnerabilities
- TI-2026-46366 Server-side request forgery in mlflow KEVCVSS 3.1CRITICAL 9.3
- TI-2023-03518 Absolute Path Traversal in mlflow/mlflow CVSS 3.1CRITICAL 10.0
- TI-2023-01113 Path Traversal: '\..\filename' in mlflow/mlflow CVSS 3.1CRITICAL 9.8
- TI-2025-31759 Redis Lua Use-After-Free may lead to remote code execution CVSS 3.1CRITICAL 10.0
- TI-2026-81527 Code execution via scorer deserialization in MLflow servers CVSS 3.1CRITICAL 9.8
- TI-2025-14028 Command Injection in mlflow/mlflow CVSS 3.1CRITICAL 10.0
Sources
- CVE-2025-53365 · CVE Program
- CVE-2025-53365 · NVD
- FIRST EPSS
- GHSA-j975-95f5-7wqh · GitHub Advisory Database · CC BY 4.0
- CVE-2025-53365 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences