CVE-2026-85700 PUBLISHED

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.

• George Chen finder

• GitHub Issue #13165
• https://github.com/onyx-dot-app/onyx
• https://github.com/onyx-dot-app/onyx/blob/v4.6.6/backend/onyx/server/features/tool/models.py
• https://github.com/onyx-dot-app/onyx/blob/v4.6.6/backend/onyx/server/features/tool/api.py
• VulnCheck Advisory: Onyx 4.6.6 Custom Tool Secret Header Disclosure via Tool Endpoints

• Insufficiently Protected Credentials CWE