# CVE-2026-71424

## Summary

- **CVE ID:** CVE-2026-71424
- **Severity:** CRITICAL
- **CVSS Score:** 9.6 (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:** Aug 17, 2026
- **Last Modified:** Aug 18, 2026

## 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.

## Affected Products

- onyx-dot-app — onyx (< 3.1.10)
- onyx-dot-app — onyx (>= 3.2.0, < 3.2.14)
- onyx-dot-app — onyx (>= 3.3.0-beta.0, < 4.0.0)

## References

- [CNA](https://github.com/onyx-dot-app/onyx/security/advisories/GHSA-q62f-rv3h-f822)
- [CNA](https://github.com/onyx-dot-app/onyx/pull/11238)
- [CNA](https://github.com/onyx-dot-app/onyx/pull/11242)
- [CNA](https://github.com/onyx-dot-app/onyx/pull/11243)
- [CNA](https://github.com/onyx-dot-app/onyx/commit/3f3d79d1a7722fdc84a1c61c8aa830d890017e9e)
- [CNA](https://github.com/onyx-dot-app/onyx/commit/4001cedd0a8968723bfe95dd188914ed56777910)
- [CNA](https://github.com/onyx-dot-app/onyx/commit/b103937888fd5008067c2bb6eb6e5424576394f2)
- [CNA](https://github.com/onyx-dot-app/onyx/releases/tag/v4.0.0)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.29%
- **EPSS Percentile:** 21.5

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-11._