Vulnerability · Published Sep 4, 2026 · Assigned by VulnCheck
CVE-2026-85700Onyx 4.6.6 Custom Tool Secret Header Disclosure via Tool Endpoints
Medium 6.5
In plain English
A medium-severity security flaw in onyx from onyx-dot-app. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 44% of all known vulnerabilities).
Severity (CVSS 3.1)6.5Medium
Exploit odds (30 days)0.5%top 56.2% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known
Official 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 (as reported)
| Vendor | Product | Versions |
|---|---|---|
| onyx-dot-app | onyx | 0 – through 4.6.6 |
Weakness: CWE-522 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
References
- GitHub Issue #13165 issue-tracking
- https://github.com/onyx-dot-app/onyx product
- https://github.com/onyx-dot-app/onyx/blob/v4.6.6/backend/onyx/server/features/tool/models.py technical-description
- https://github.com/onyx-dot-app/onyx/blob/v4.6.6/backend/onyx/server/features/tool/api.py technical-description
- VulnCheck Advisory: Onyx 4.6.6 Custom Tool Secret Header Disclosure via Tool Endpoints third-party-advisory