CVE-2025-53365
EPSS 0.14%MCP Python SDK has Unhandled Exception in Streamable HTTP Transport, Leading to Denial of Service
Published: 7/4/2025Modified: 7/5/2025
Description
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.
Affected packages (1)
- PyPI/mcpfrom 0, < 1.10.0
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | 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 |
References (6)
- ADVISORYhttps://nvd.nist.gov/vuln/detail/CVE-2025-53365
- PATCHhttps://github.com/modelcontextprotocol/python-sdk
- WEBhttps://github.com/modelcontextprotocol/python-sdk/commit/7b420656de48cfdb90b39eb582e60b6d55c2f891
- WEBhttps://github.com/modelcontextprotocol/python-sdk/pull/967
- WEBhttps://github.com/modelcontextprotocol/python-sdk/releases/tag/v1.10.0
- WEBhttps://github.com/modelcontextprotocol/python-sdk/security/advisories/GHSA-j975-95f5-7wqh