PYSEC-2026-1618
See a problem?- Import Source
- https://github.com/pypa/advisory-database/blob/main/vulns/mcp/PYSEC-2026-1618.yaml
- JSON Data
- https://api.osv.dev/v1/vulns/PYSEC-2026-1618
- Aliases
- Published
- 2026-07-07T16:02:56.105116Z
- Modified
- 2026-07-07T17:47:04.395676741Z
- Severity
-
- 8.7 (High) CVSS_V4 - 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 CVSS Calculator
- Summary
- MCP Python SDK has Unhandled Exception in Streamable HTTP Transport, Leading to Denial of Service
- Details
-
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.
Thank you to Rich Harang for reporting this issue.
- References
-
- https://github.com/modelcontextprotocol/python-sdk/security/advisories/GHSA-j975-95f5-7wqh
- https://nvd.nist.gov/vuln/detail/CVE-2025-53365
- 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://pypi.org/project/mcp
- https://github.com/advisories/GHSA-j975-95f5-7wqh
Affected packages
PyPI / mcp
Package
- Name
- mcp
- View open source insights on deps.dev
- Purl
- pkg:pypi/mcp
Affected ranges
- Type
- ECOSYSTEM
- Events
-
Introduced0Unknown introduced version / All previous versions are affectedFixed1.10.0