{"id":"CVE-2026-71424","aliases":["EUVD-2026-60479","GHSA-q62f-rv3h-f822"],"status":"published","title":"Onyx: Cross-user OAuth-token leak via /api/mcp/servers* for per-user MCP servers","description":"Onyx is an open-source AI platform. Prior to 3.1.10, 3.2.14, and 4.0.0, Onyx's GET /api/mcp/servers and GET /api/mcp/servers/persona/{persona_id} endpoints expose another user's OAuth Authorization header because OnyxTokenStorage.set_tokens and OnyxTokenStorage.set_client_info in backend/onyx/server/features/mcp/api.py copy per-user tokens into a shared admin MCPConnectionConfig row and _db_mcp_server_to_api_mcp_server returns that row through auth_template.headers to any BASIC_ACCESS user. This issue is fixed in versions 3.1.10, 3.2.14, and 4.0.0.","severity":{"version":"3.1","score":9.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N","level":"critical","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00488,"percentile":0.42371,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-200","CWE-863"],"published":"2026-08-17T21:28:32Z","modified":"2026-10-28T02:30:54Z","products":[{"vendor":"onyx-dot-app","product":"onyx"}],"references":[{"url":"https://github.com/onyx-dot-app/onyx/security/advisories/GHSA-q62f-rv3h-f822","tags":["x_refsource_CONFIRM","advisory"]},{"url":"https://github.com/onyx-dot-app/onyx/pull/11238","tags":["x_refsource_MISC","fix"]},{"url":"https://github.com/onyx-dot-app/onyx/pull/11242","tags":["x_refsource_MISC","fix"]},{"url":"https://github.com/onyx-dot-app/onyx/pull/11243","tags":["x_refsource_MISC","fix"]},{"url":"https://github.com/onyx-dot-app/onyx/commit/3f3d79d1a7722fdc84a1c61c8aa830d890017e9e","tags":["x_refsource_MISC","fix"]},{"url":"https://github.com/onyx-dot-app/onyx/commit/4001cedd0a8968723bfe95dd188914ed56777910","tags":["x_refsource_MISC","fix"]},{"url":"https://github.com/onyx-dot-app/onyx/commit/b103937888fd5008067c2bb6eb6e5424576394f2","tags":["x_refsource_MISC","fix"]},{"url":"https://github.com/onyx-dot-app/onyx/releases/tag/v4.0.0","tags":["x_refsource_MISC","web"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/71xxx/CVE-2026-71424.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-71424","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-71424","title":"Onyx: Cross-user OAuth-token leak via /api/mcp/servers* for per-user MCP servers","description":"Onyx is an open-source AI platform. Prior to 3.1.10, 3.2.14, and 4.0.0, Onyx's GET /api/mcp/servers and GET /api/mcp/servers/persona/{persona_id} endpoints expose another user's OAuth Authorization header because OnyxTokenStorage.set_tokens and OnyxTokenStorage.set_client_info in backend/onyx/server/features/mcp/api.py copy per-user tokens into a shared admin MCPConnectionConfig row and _db_mcp_server_to_api_mcp_server returns that row through auth_template.headers to any BASIC_ACCESS user. This issue is fixed in versions 3.1.10, 3.2.14, and 4.0.0.","status":"published","published":"2026-08-17T21:28:32.814Z","modified":"2026-08-18T17:47:10.013Z","cvss":[{"version":"3.1","score":9.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N","level":"critical","assessor":"cna"}],"cwes":["CWE-200","CWE-863"],"updated_at":"2026-11-02T14:19:49.559463Z"}],"euvd":[{"id":"EUVD-2026-60479","description":"Onyx is an open-source AI platform. Prior to 3.1.10, 3.2.14, and 4.0.0, Onyx's GET /api/mcp/servers and GET /api/mcp/servers/persona/{persona_id} endpoints expose another user's OAuth Authorization header because OnyxTokenStorage.set_tokens and OnyxTokenStorage.set_client_info in backend/onyx/server/features/mcp/api.py copy per-user tokens into a shared admin MCPConnectionConfig row and _db_mcp_server_to_api_mcp_server returns that row through auth_template.headers to any BASIC_ACCESS user. This issue is fixed in versions 3.1.10, 3.2.14, and 4.0.0.","status":"published","published":"2026-08-17T21:28:32Z","modified":"2026-08-18T17:47:10Z","cvss":[{"version":"3.1","score":9.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N","level":"critical"}],"updated_at":"2026-11-02T18:01:46.405062Z"}],"nvd":[{"id":"CVE-2026-71424","description":"Onyx is an open-source AI platform. Prior to 3.1.10, 3.2.14, and 4.0.0, Onyx's GET /api/mcp/servers and GET /api/mcp/servers/persona/{persona_id} endpoints expose another user's OAuth Authorization header because OnyxTokenStorage.set_tokens and OnyxTokenStorage.set_client_info in backend/onyx/server/features/mcp/api.py copy per-user tokens into a shared admin MCPConnectionConfig row and _db_mcp_server_to_api_mcp_server returns that row through auth_template.headers to any BASIC_ACCESS user. This issue is fixed in versions 3.1.10, 3.2.14, and 4.0.0.","status":"published","published":"2026-08-17T22:17:26.527Z","modified":"2026-10-22T22:10:00.25Z","cvss":[{"version":"3.1","score":9.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N","level":"critical","assessor":"secondary"}],"cwes":["CWE-200","CWE-863"],"updated_at":"2026-11-02T14:12:38.647684Z"}],"osv":[{"id":"CVE-2026-71424","title":"Onyx: Cross-user OAuth-token leak via /api/mcp/servers* for per-user MCP servers","description":"Onyx is an open-source AI platform. Prior to 3.1.10, 3.2.14, and 4.0.0, Onyx's GET /api/mcp/servers and GET /api/mcp/servers/persona/{persona_id} endpoints expose another user's OAuth Authorization header because OnyxTokenStorage.set_tokens and OnyxTokenStorage.set_client_info in backend/onyx/server/features/mcp/api.py copy per-user tokens into a shared admin MCPConnectionConfig row and _db_mcp_server_to_api_mcp_server returns that row through auth_template.headers to any BASIC_ACCESS user. This issue is fixed in versions 3.1.10, 3.2.14, and 4.0.0.","status":"published","published":"2026-08-17T21:28:32.814Z","modified":"2026-10-28T02:30:54.133405766Z","cvss":[{"version":"3.1","score":9.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N","level":"critical"}],"cwes":["CWE-200","CWE-863"],"updated_at":"2026-11-02T15:45:15.164658Z"}]}}