{"items":[{"id":"NVI-00016165","kind":"vulnerability","title":"MCP Python SDK: WebSocket server transport does not support Host/Origin validation","revision":2,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected.","NVD lastModified does not establish freshness of every associated CPE record."],"lifecycle":"active","identifiers":["GHSA-vj7q-gjh5-988w","CVE-2026-59950"],"plain_summary":"GitHub lists this reviewed advisory for mcp. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-083b19a392787589379c23c5bcc45a0b"],"action_type":"investigate","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[{"kind":"CVSS","as_of":"2026-10-24T21:10:00.130Z","value":"8.1 HIGH (3.1)","meaning":"nvd@nist.gov severity; no combined Null risk score.","source_id":"sr-083b19a392787589379c23c5bcc45a0b"},{"kind":"CVSS","as_of":"2026-10-24T21:10:00.130Z","value":"7.6 HIGH (4.0)","meaning":"security-advisories@github.com severity; no combined Null risk score.","source_id":"sr-083b19a392787589379c23c5bcc45a0b"}],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-362cd4728cf8e13db471dbbaae33ee92","url":"https://github.com/advisories/GHSA-vj7q-gjh5-988w","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-vj7q-gjh5-988w","publisher":"GitHub Advisory Database","observed_at":"2026-11-04T09:59:26.779Z"},{"id":"sr-083b19a392787589379c23c5bcc45a0b","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-59950","basis":"official_catalog","notes":"This product uses data from the NVD API but is not endorsed or certified by the NVD.","title":"CVE-2026-59950","publisher":"NIST National Vulnerability Database","observed_at":"2026-11-08T08:05:01.676Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-362cd4728cf8e13db471dbbaae33ee92"],"technology":"mcp","known_exclusions":[],"conditions_summary":"### Summary\nIn affected versions, the deprecated WebSocket server transport (`mcp.server.websocket.websocket_server`) accepted the WebSocket handshake without applying any `Host` or `Origin` header validation. The `TransportSecuritySettings` mechanism that the SSE and Streamable HTTP transports use for this purpose was not wired into the WebSocket transport, so there was no SDK-level way to restrict which origins could connect.\n\n### Am I affected?\nOnly if a developer's application server exposes `mcp.server.websocket.websocket_server`. This transport has never been part of the MCP specification, is marked deprecated, and is not reachable through `FastMCP` — a developer must have wired it into an ASGI application themselves. Servers using stdio, SSE, or Streamable HTTP are not affected by this advisory.\n\n### Details\n`websocket_server()` constructed a Starlette `WebSocket` and called `accept(subprotocol=\"mcp\")` immediately, with no inspection of the connection's headers. By contrast, `SseServerTransport` and `StreamableHTTPServerTransport` accept an optional `security_settings: TransportSecuritySettings` and run `TransportSecurityMiddleware.validate_request()` against the incoming `H","public_affected_ranges":["< 1.28.1"]}],"null_published_at":"2026-11-08T19:53:44.019Z","source_updated_at":"2026-07-16T20:14:35.000Z","source_disclosed_at":"2026-07-16T20:14:34.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"Source facts changed; compare the preserved prior revision.","null_first_observed_at":"2026-11-04T09:59:26.779Z"},{"id":"NVI-00016165","kind":"vulnerability","title":"MCP Python SDK: WebSocket server transport does not support Host/Origin validation","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-vj7q-gjh5-988w","CVE-2026-59950"],"plain_summary":"GitHub lists this reviewed advisory for mcp. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-362cd4728cf8e13db471dbbaae33ee92"],"action_type":"investigate","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-362cd4728cf8e13db471dbbaae33ee92","url":"https://github.com/advisories/GHSA-vj7q-gjh5-988w","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-vj7q-gjh5-988w","publisher":"GitHub Advisory Database","observed_at":"2026-11-04T09:59:26.779Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-362cd4728cf8e13db471dbbaae33ee92"],"technology":"mcp","known_exclusions":[],"conditions_summary":"### Summary\nIn affected versions, the deprecated WebSocket server transport (`mcp.server.websocket.websocket_server`) accepted the WebSocket handshake without applying any `Host` or `Origin` header validation. The `TransportSecuritySettings` mechanism that the SSE and Streamable HTTP transports use for this purpose was not wired into the WebSocket transport, so there was no SDK-level way to restrict which origins could connect.\n\n### Am I affected?\nOnly if a developer's application server exposes `mcp.server.websocket.websocket_server`. This transport has never been part of the MCP specification, is marked deprecated, and is not reachable through `FastMCP` — a developer must have wired it into an ASGI application themselves. Servers using stdio, SSE, or Streamable HTTP are not affected by this advisory.\n\n### Details\n`websocket_server()` constructed a Starlette `WebSocket` and called `accept(subprotocol=\"mcp\")` immediately, with no inspection of the connection's headers. By contrast, `SseServerTransport` and `StreamableHTTPServerTransport` accept an optional `security_settings: TransportSecuritySettings` and run `TransportSecurityMiddleware.validate_request()` against the incoming `H","public_affected_ranges":["< 1.28.1"]}],"null_published_at":"2026-11-04T10:04:27.900Z","source_updated_at":"2026-07-16T20:14:35.000Z","source_disclosed_at":"2026-07-16T20:14:34.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"First indexed by Null; source disclosure date is shown separately.","null_first_observed_at":"2026-11-04T09:59:26.779Z"}],"next_cursor":null,"snapshot_revision":"42594"}