CVE-2026-116686
6.5 MEDIUMpublic exploit availablePublished 2026-10-27 · Updated 2026-10-27
AI analysis for this CVE has not been generated yet. Raw NVD data is shown below.
NVD description
The Model Context Protocol Python SDK is the official Python SDK for Model Context Protocol servers and clients. From 1.10.0 until 1.30.0 and 2.2.0, ClientSession, ClientSessionGroup, and Client tool calls validate server-declared outputSchema documents with jsonschema's default resolver, causing an unresolved $ref value to fetch an HTTP, HTTPS, or file URL from the client's network and filesystem context. A server can trigger blind requests or local-file reads and can stall every session in the process because resolution runs synchronously on the event loop without a timeout. This issue is fixed in versions 1.30.0 and 2.2.0.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Weaknesses
CWE-918
Public exploit & PoC references
- https://github.com/modelcontextprotocol/python-sdk/commit/5ebdfed4060d8e5b11b8e2348f86bad4d1fb8836
- https://github.com/modelcontextprotocol/python-sdk/commit/6705402e246dc4eb1fcdf4d9902b78d3c9c36e1b
- https://github.com/modelcontextprotocol/python-sdk/pull/3394
- https://github.com/modelcontextprotocol/python-sdk/pull/3396
- https://github.com/modelcontextprotocol/python-sdk/releases/tag/v1.30.0
- https://github.com/modelcontextprotocol/python-sdk/releases/tag/v2.2.0
- https://github.com/modelcontextprotocol/python-sdk/security/advisories/GHSA-rwrf-2pqf-9j8j
All references
- https://github.com/modelcontextprotocol/python-sdk/commit/5ebdfed4060d8e5b11b8e2348f86bad4d1fb8836
- https://github.com/modelcontextprotocol/python-sdk/commit/6705402e246dc4eb1fcdf4d9902b78d3c9c36e1b
- https://github.com/modelcontextprotocol/python-sdk/pull/3394
- https://github.com/modelcontextprotocol/python-sdk/pull/3396
- https://github.com/modelcontextprotocol/python-sdk/releases/tag/v1.30.0
- https://github.com/modelcontextprotocol/python-sdk/releases/tag/v2.2.0
- https://github.com/modelcontextprotocol/python-sdk/security/advisories/GHSA-rwrf-2pqf-9j8j
Source data: NVD (nvd.nist.gov), public domain. Exploit-DB.ai adds local AI analysis for defensive use only.
Related CVEs
- HIGHCVE-2020-37278PoC
- HIGHCVE-2023-54402PoC
- MEDIUMCVE-2024-34319
- UNSCOREDCVE-2026-0311
- LOWCVE-2026-100104
- MEDIUMCVE-2026-100251
- MEDIUMCVE-2026-100257
- MEDIUMCVE-2026-100279
Related by shared AI tags and CWE weakness class. Browse the full archive.