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.

Metrics

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required Low

Scope Changed

Confidentiality Impact High

Integrity Impact High

Availability Impact None

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Affected Vendors & Products

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Vendors Products
References
Link Providers
https://github.com/onyx-dot-app/onyx/commit/3f3d79d1a7722fdc84a1c61c8aa830d890017e9e cve-icon cve-icon
https://github.com/onyx-dot-app/onyx/commit/4001cedd0a8968723bfe95dd188914ed56777910 cve-icon cve-icon
https://github.com/onyx-dot-app/onyx/commit/b103937888fd5008067c2bb6eb6e5424576394f2 cve-icon cve-icon
https://github.com/onyx-dot-app/onyx/pull/11238 cve-icon cve-icon
https://github.com/onyx-dot-app/onyx/pull/11242 cve-icon cve-icon
https://github.com/onyx-dot-app/onyx/pull/11243 cve-icon cve-icon
https://github.com/onyx-dot-app/onyx/releases/tag/v4.0.0 cve-icon cve-icon
https://github.com/onyx-dot-app/onyx/security/advisories/GHSA-q62f-rv3h-f822 cve-icon cve-icon
History

Mon, 17 Aug 2026 21:45:00 +0000

Type Values Removed Values Added
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.
Title Onyx: Cross-user OAuth-token leak via /api/mcp/servers* for per-user MCP servers
Weaknesses CWE-200
CWE-863
References
Metrics cvssV3_1

{'score': 9.6, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N'}
cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-08-17T21:28:32.814Z

Reserved: 2026-08-06T16:28:51.182Z

Link: CVE-2026-71424

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-17T22:17:26.527

Modified: 2026-08-17T22:17:26.527

Link: CVE-2026-71424

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-18T00:00:05Z