# CVE-2026-85700

## Summary

- **CVE ID:** CVE-2026-85700
- **Severity:** HIGH
- **CVSS Score:** 7.1 (CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N)
- **CWE:** CWE-522
- **Published:** Sep 4, 2026
- **Last Modified:** Sep 4, 2026

## 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.

## Affected Products

- onyx-dot-app — onyx (0)

## References

- [CNA](https://github.com/onyx-dot-app/onyx/issues/13165)
- [CNA](https://github.com/onyx-dot-app/onyx)
- [CNA](https://github.com/onyx-dot-app/onyx/blob/v4.6.6/backend/onyx/server/features/tool/models.py)
- [CNA](https://github.com/onyx-dot-app/onyx/blob/v4.6.6/backend/onyx/server/features/tool/api.py)
- [CNA](https://www.vulncheck.com/advisories/onyx-4.6.6-custom-tool-secret-header-disclosure-via-tool-endpoints)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.29%
- **EPSS Percentile:** 21.2

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._