CVE-2026-85700 [MEDIUM] – Onyx 4.6.6 fails to properly restrict access to custom tool credentials stored in custom_h

Onyx 4.6.6 fails to properly restrict access to custom tool credentials stored in custom_headers, allowing any authenticated user to read admin-defined API keys. Attackers with basic authentication can call GET /tool/{tool_id} or GET /tool endpoints to retrieve plaintext authorization headers and third-party API credentials, then use them to directly access upstream APIs.