CVE-2026-71424

Received Received - Intake

OAuth Token Exposure in Onyx AI Platform

Publication date: 2026-08-17

Last updated on: 2026-08-17

Assigner: GitHub, Inc.

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.

CVSS Scores

EPSS Scores

Probability:
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Meta Information

Published

2026-08-17

Last Modified

2026-08-17

Generated

2026-08-18

AI Q&A

2026-08-18

EPSS Evaluated

N/A

NVD

CVE-2026-71424

Affected Vendors & Products

Vendor	Product	Version / Range
onyx	onyx	to 3.1.10 (inc)
onyx	onyx	to 3.2.14 (inc)
onyx	onyx	to 4.0.0 (inc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-200	The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.
CWE-863	The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.

Attack-Flow Graph

Executive Summary

This vulnerability in Onyx, an open-source AI platform, involves two API endpoints (GET /api/mcp/servers and GET /api/mcp/servers/persona/{persona_id}) exposing another user's OAuth Authorization header. The issue occurs because token storage functions copy per-user tokens into a shared admin row, which is then returned to any BASIC_ACCESS user via auth_template.headers.

Detection Guidance

This vulnerability involves exposed OAuth Authorization headers in Onyx API endpoints. To detect it, inspect network traffic for GET requests to /api/mcp/servers or /api/mcp/servers/persona/{persona_id} endpoints. Check if responses contain Authorization headers belonging to other users. Verify Onyx versions are below 3.1.10, 3.2.14, or 4.0.0.

Impact Analysis

An attacker with BASIC_ACCESS could access another user's OAuth Authorization header, potentially allowing them to impersonate that user, access their data, or perform actions on their behalf. This could lead to unauthorized access to sensitive information or system functions.

Compliance Impact

This vulnerability could violate GDPR and HIPAA by exposing sensitive user data (OAuth tokens) to unauthorized parties. GDPR requires protecting personal data, while HIPAA mandates safeguarding protected health information. The exposure of OAuth tokens may lead to unauthorized access to regulated data.

Mitigation Strategies

Immediately upgrade Onyx to versions 3.1.10, 3.2.14, or 4.0.0 or later to patch the vulnerability. Review and restrict access to the affected endpoints GET /api/mcp/servers and GET /api/mcp/servers/persona/{persona_id} to prevent unauthorized access to OAuth Authorization headers.

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