CVE-2026-85700
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.29%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 4.0
- 7.1 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.29% probability · 21th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-522
- Source
- disclosure@vulncheck.com
References
- https://github.com/onyx-dot-app/onyx
- https://github.com/onyx-dot-app/onyx/blob/v4.6.6/backend/onyx/server/features/tool/api.py
- 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/issues/13165
- https://www.vulncheck.com/advisories/onyx-4.6.6-custom-tool-secret-header-disclosure-via-tool-endpoints
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.