---
id: CVE-2026-71424
title: Onyx is an open-source AI platform
summary: >-
  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_tok…
severity: critical
cvss: 9.6
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N'
cwe:
  - CWE-200
  - CWE-863
published: '2026-08-17'
updated: '2026-09-18'
sourceUpdated: '2026-09-18T20:09:01.757'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-71424'
references:
  - url: >-
      https://github.com/onyx-dot-app/onyx/commit/3f3d79d1a7722fdc84a1c61c8aa830d890017e9e
    label: security-advisories@github.com
  - url: >-
      https://github.com/onyx-dot-app/onyx/commit/4001cedd0a8968723bfe95dd188914ed56777910
    label: security-advisories@github.com
  - url: >-
      https://github.com/onyx-dot-app/onyx/commit/b103937888fd5008067c2bb6eb6e5424576394f2
    label: security-advisories@github.com
  - url: 'https://github.com/onyx-dot-app/onyx/pull/11238'
    label: security-advisories@github.com
  - url: 'https://github.com/onyx-dot-app/onyx/pull/11242'
    label: security-advisories@github.com
  - url: 'https://github.com/onyx-dot-app/onyx/pull/11243'
    label: security-advisories@github.com
  - url: 'https://github.com/onyx-dot-app/onyx/releases/tag/v4.0.0'
    label: security-advisories@github.com
  - url: >-
      https://github.com/onyx-dot-app/onyx/security/advisories/GHSA-q62f-rv3h-f822
    label: security-advisories@github.com
tags:
  - nvd
epss: 0.00488
epssPercentile: 0.39368
ingestedAt: '2026-09-18T20:51:25.625Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.