CVE-2026-85700: Onyx 4.6.6 Custom Tool Secret Header Disclosure via Tool Endpoints
Onyx 4.6.6 fails to properly restrict access to custom tool credentials stored in customheaders, allowing any authenticated user to read admin-defined API keys. Attackers with basic authentication can call GET /tool/{toolid} or GET /tool endpoints to retrieve plaintext authorization headers and third-party API credentials, then use them to directly access upstream APIs.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Onyxto a version that resolves this vulnerability.Fixed in 4.6.6
Event History
Frequently Asked Questions
What level of access does an attacker need?
Any authenticated Onyx user can exploit the issue; administrator privileges are not required. The attack can be performed with basic authentication.
Which requests expose the credentials?
The affected endpoints are GET /tool/{tool_id} and GET /tool. An authenticated user can use them to retrieve plaintext authorization headers and third-party API credentials stored in custom_headers.
What can an attacker do with exposed values?
The disclosed credentials can be used to directly access the corresponding upstream APIs. The impact depends on the permissions granted to each admin-defined API key or authorization header.