{"items":[{"id":"NVI-00011938","kind":"vulnerability","title":"MCP TypeScript client SDK: HTTP client transports and OAuth requests followed cross-origin redirects and re-sent custom headers and request bodies","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-6prh-2h8m-c8cw","CVE-2026-111769"],"plain_summary":"GitHub lists this reviewed advisory for @modelcontextprotocol/sdk, @modelcontextprotocol/client. 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-667b3d1af9701b4de06852eacd2017f2"],"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":"2026-10-20T18:26:32.000Z","value":"6.5 medium","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-667b3d1af9701b4de06852eacd2017f2"}],"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-667b3d1af9701b4de06852eacd2017f2","url":"https://github.com/advisories/GHSA-6prh-2h8m-c8cw","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-6prh-2h8m-c8cw","publisher":"GitHub Advisory Database","observed_at":"2026-10-31T23:13:39.183Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-667b3d1af9701b4de06852eacd2017f2"],"technology":"@modelcontextprotocol/sdk","known_exclusions":[],"conditions_summary":"### Summary\nIn affected versions, the SDK's HTTP client transports and OAuth requests followed redirects to any origin.\n\nIf an MCP server or authorization server redirected a request to another origin, that origin received custom request headers (such as an `X-API-Key` set in `requestInit.headers`) and the `mcp-session-id` header. On a `307` or `308` it also received the request body, including OAuth token requests with their `refresh_token` and `client_secret`.\n\nOn current runtimes `fetch` already drops the `Authorization` header across origins.\n\n### Am I affected?\nYes, if your application uses `StreamableHTTPClientTransport`, `SSEClientTransport`, or the SDK's OAuth client functions such as `auth()`. stdio clients are not affected.\n\nAffected versions:\n\n- `@modelcontextprotocol/sdk` all versions through 1.31.0\n- `@modelcontextprotocol/client` 2.0.0 through 2.2.0\n\n### Fix\nUpgrade to:\n\n- 1.x: `@modelcontextprotocol/sdk` 1.32.0 or later\n- 2.x: `@modelcontextprotocol/client` 2.3.0 or later\n\nRedirects are now followed only within the same origin, and not at all in browsers. If your MCP server or authorization server redirects to another origin on purpose, configure the final URL instea","public_affected_ranges":["< 1.32.0"]},{"certainty":"source_listed","source_ids":["sr-667b3d1af9701b4de06852eacd2017f2"],"technology":"@modelcontextprotocol/client","known_exclusions":[],"conditions_summary":"### Summary\nIn affected versions, the SDK's HTTP client transports and OAuth requests followed redirects to any origin.\n\nIf an MCP server or authorization server redirected a request to another origin, that origin received custom request headers (such as an `X-API-Key` set in `requestInit.headers`) and the `mcp-session-id` header. On a `307` or `308` it also received the request body, including OAuth token requests with their `refresh_token` and `client_secret`.\n\nOn current runtimes `fetch` already drops the `Authorization` header across origins.\n\n### Am I affected?\nYes, if your application uses `StreamableHTTPClientTransport`, `SSEClientTransport`, or the SDK's OAuth client functions such as `auth()`. stdio clients are not affected.\n\nAffected versions:\n\n- `@modelcontextprotocol/sdk` all versions through 1.31.0\n- `@modelcontextprotocol/client` 2.0.0 through 2.2.0\n\n### Fix\nUpgrade to:\n\n- 1.x: `@modelcontextprotocol/sdk` 1.32.0 or later\n- 2.x: `@modelcontextprotocol/client` 2.3.0 or later\n\nRedirects are now followed only within the same origin, and not at all in browsers. If your MCP server or authorization server redirects to another origin on purpose, configure the final URL instea","public_affected_ranges":[">= 2.0.0, < 2.3.0"]}],"null_published_at":"2026-11-01T01:03:56.616Z","source_updated_at":"2026-10-20T18:26:32.000Z","source_disclosed_at":"2026-10-20T18:26:30.000Z","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":"2026-10-31T23:13:39.183Z"}],"next_cursor":null,"snapshot_revision":"42594"}