CVE-2025-53365High▾ TwilightMCP Python SDK has Unhandled Exception in Streamable HTTP Transport, Leading to Denial of Service
▾ Twilight zone — High severity, or a signal on a lesser flaw
impact 41.3 · likelihood 0.1 · exploitation 0
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Exploit-prediction probability, daily snapshots since Jul 31.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via OSV
Last analysed / modified upstream
0.4%
0.4% → 0.4%
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.
mcp < 1.10.0Upgrade to a patched release:
mcp 1.10.0Connected by shared product, vendor, weakness, or advisory.
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